Library 


CONCRETE   GARAGES 


THE    FIREPROOF   HOME  U&i\ 
FOR    THE    AUTOMOBILE';/;.-    n: 


PUBLISHED  BY 


THE  ATLAS  PORTLAND  CEMENT  COMPANY 

30     BROAD     STREET 
NEW  YORK 


TAU/ 


Library 


Engineering 
Library 


Copyrighted  by 

THE  ATLAS  PORTLAND  CEMENT  COMPANY 

30  Broad  Street.  New  York 

All  Rights  Reserved 

First  Edition 


I 


CONCRETE  GARAGES 


With  the  advent  of  the  automobile  and  its  growing  popularity,  especially 
among  the  people  living  in  suburban  towns,  there  has  come  a  demand  for  a 
new  class  of  building — the  private  garage.  The  necessary  storage  of  oils, 
gasoline  and  other  combustible  materials,  makes  the  garage  a  veritable  fire- 
trap,  unless  a  fireproof  building  is  erected. 

Concrete,  by  reason  of  its  adaptability  to  varying  conditions,  is  the  cheapest 
satisfactory  fireproof  building  material,  and  the  absurdity  of  storing  a  valuable 
automobile  in  a  building  liable  to  burn  at  any  moment,  when,  for  a  small  dif- 
ference in  price,  a  fraction  of  the  cost  of  the  automobile,  a  fireproof  building 
can  be  built,  is  readily  apparent. 

Many  automobile  owners  have  realized  this  situation,  and  the  illustrations 
in  this  book  show  a  few  simple  designs  in  concrete  garages  which  have  been 
built  for  the  proper  housing  of  automobiles  and  the  protection  of  the  property. 

It  is  hardly  necessary  to  say  that  wood  is  not  a  proper  material  for  the  con- 
struction of  garages.  Moreover,  wood  floors  become  soaked  with  oil  and 
quickly  rot  tires.  Aside  from  being  inflammable,  the  high  cost  of  lumber  and 
of  the  skilled  labor  necessary  renders  the  difference  in  price  between  wood  and 
concrete  a  negligible  quantity. 

Brick  work  and  masonry  are  as  a  rule  very  much  more  expensive  than  con- 
crete, while  offering  no  additional  advantages. 

There  are  several  ways  of  using  concrete  in  garage  construction,  each  of 
which  will  give  good  results,  the  best  methods  being  determined  largely  by 
local  conditions,  such  as  the  supply  of  skilled  or  unskilled  labor  and  the  quality 
of  material  to  be  had.  Simple  one-story  garages  can  be  constructed  without 
difficulty  under  the  direction  of  a  good  foreman,  but  for  the  more  elaborate 
buildings  and  those  of  more  than  one  story,  an  architect  or  engineer  thoroughly 
familiar  with  concrete  construction  should  be  employed.  This  is  essential 
when  reinforced  concrete  floors  are  to  be  built. 

The  following  methods  of  building  concrete  garages  are  the  most  popular, 
and  used  either  singly  or  in  combination  will  give  satisfactory  results. 

i. — Mass  or  reinforced  concrete. 

2. — Concrete  hollow  tile. 

3. — Concrete  block. 

4. — Pipe  frame  with  wire  lath  and  stucco. 

5. — Wood  stud  frame  and  stucco. 


78E?451 


GENERAL  DIRECTIONS. 

*The  selection  of  materials  for  building  with  concrete  should  be  carefully 
undertaken,  as  without  the  best  material  a  first  class  job  cannot  be  expected. 

These  brief  rules  should  always  be  kept  in  mind:  ist — Use  clean  coarse 
sand,  broken  stone  or  clean  screened  gravel  and  Atlas  Portland  Cement.  2d — 
Make  sure  the  concrete  is  thoroughly  mixed.  3d — That  sufficient  water  is 
added  to  produce  a  mushy  mixture.  4th — The  concrete  is  used  before  it  gets 
its  initial  set — the  result  will  be  a  hard,  dense  concrete. 

The  selection  of  the  aggregate  (sand  and  broken  stone  or  gravel)  will  play 
an  important  part  in  the  appearance  of  the  finished  work,  and  where  a  particu- 
lar shade  or  color  is  desired,  it  is  recommended  that  a  sample  batch  of  concrete 
be  made,  using  exactly  the  material  that  is  to  be  used  in  the  work. 

Atlas  Portland  Cement  is  particularly  light  in  color,  and,  therefore,  pecu- 
liarly adapted  to  obtaining  beautiful  effects. 

MASS  OR  REINFORCED  CONCRETE  CONSTRUCTION. 

Mass  concrete,  by  which  is  meant  solid  concrete,  built  in  place  between 
temporary  wooden  forms,  is  a  most  durable  and  substantial  type.  Floors  may 
be  built  of  the  same  material,  but  must  be  properly  reinforced  with  steel. 

In  preparing  the  footing  for  a  garage,  excavate  a  trench  to  the  depth  below 
the  frost  line,  six  inches  wider  than  the  proposed  wall,  and  fill  to  within  8 
inches  of  the  ground  level  with  concrete — i  part  Atlas  Portland  Cement,  3 
parts  clean  coarse  sand,  6  parts  broken  stone  or  gravel.  After  the  concrete  is 
sufficiently  hard  to  withstand  the  weight  build  the  fforms  for  the  proposed 
wall  in  the  center  of  the  footing  and  fill  with  concrete — i  part  Atlas  Portland 
Cement,  2  parts  clean  coarse  sand,  4  parts  broken  stone  or  gravel — using  a 
stable  or  coal  fork  to  work  the  large  pieces  of  aggregate  away  from  the  sur- 
face, letting  the  mortar  and  fine  material  through  so  as  to  make  a  dense, 
smooth,  hard  surface.  The  forms  for  the  walls  may  be  taken  off  in  48  hours 
in  warm  weather,  but  should  remain  longer  if  the  weather  is  cool.  In  cold 
weather  concrete  may  be  handled  with  excellent  results,  but  all  material  must 
be  heated  including  the  cement  and  the  water,  to  fully  80  degrees,  and  as  soon 
as  deposited  must  be  covered  and  kept  warm  until  thoroughly  set.  In  hot 
weather  concrete  should  be  kept  covered,  sheltered  from  the  sun  as  much  as 
possible  and  continually  wet  down.  You  cannot  give  concrete  too  much 
water  after  it  has  set. 

For  a  one-story  garage,  the  walls  need  not  be  over  8  inches  thick.     For  a 

*For  detailed  information  as  to  the  selection  of  materials  and  the  methods  of  mix- 
ing and  depositing  concrete,  see  our  "Concrete  Construction  About  the  Home  and  on 
the  Farm,"  free  upon  request. 

fSee  forms  p.  19 — "Concrete  Construction  About  the  Home  and  on  the  Farm." 

7 


> 

£ 

of 

I 


//n.  Boards 

.  C/eate 


Forms  for  Mass  Concrete. 

two-story  building  make  the  first  story  10  inches  thick  and  the  second  story  8 
inches  thick.  After  the  forms  are  in  place,  it  is  desirable  to  smear  the  inner 
surface  with  petroleum  (crude  vaseline),  soft  soap  or  other  similar  material. 
After  the  forms  are  removed  and  before  the  surface  of  the  concrete  has  dried 
out,  the  board  marks  should  be  removed  by  rubbing  the  surface  with  car- 
borundum brick  and  washing  down  with  clean  water.  This  method  is  su- 
perior to  applying  a  wash  of  any  kind.  A  piece  of  hard  sandstone  will  do 
for  this  rubbing,  but  the  carborundum  will  work  faster  and  cut  cleaner. 

For  mouldings,  panels,  projections  or  recesses  corresponding  moulds 
should  be  made  in  wood  and  set  up  rigidly  with  the  wooden  form  work  and 
filled  simultaneously  with  the  rest  of  the  walls.  It  is  best  to  fill  entire  sec- 
tions of  the  wall  in  one  operation,  stopping  only  at  a  moulding  or  other  hori- 
zontal line,  as  it  is  difficult  to  bond  concrete  masses  and  the  line  of  cleavage  or 
demarcation  between  masses  of  concrete  deposited  at  different  times  is  likely 
to  show  permanently.  If  a  wall  is  to  be  stuccoed,  it  would  be  desirable  to  re- 
duce the  quantity  of  the  sand  and  allow  more  or  less  honeycombing  to  appear 
on  the  surface  of  the  work  to  give  an  additional  bond  to  the  mortar,  and  it  is 
desirable  to  wait  a  month  or  so  after  the  concrete  has  been  poured  before  the 
stucco  is  applied  to  a  concrete  wall. 

9 


bfi 

2 

oS 

o 


10 


A  good  combination  will  be  found  to  be  a  skeleton  of  reinforced  concrete 
with  piers  from  16  ft.  to  18  ft.  apart,  with  the  panel  between  the  piers  made 
of  concrete  blocks  or  tile.  The  panel  wall  may  be  made  of  solid  concrete,  the 
same  as  the  piers,  but  a  more  attractive  looking  building  and  a  more  eco- 
nomical construction  can  be  obtained  by  the  first  method.  If  more  elaborate 
effects  are  desired,  much  can  be  done  by  using  facing  of  fine  material  of 
crushed  granite  or  marble,  Atlas  Portland  Cement,  and  carefully  selected 


Garage  at  Beverly  Farms,  Mass.     Solid  Concrete. 


sand,  and  after  the  concrete  has  reached  a  proper  hardness,  tooling  the  face  so 
as  to  bring  out  the  texture  of  the  facing  mixture.  Stone  cutters'  tools  are 
used  for  this  purpose,  and  a  great  variety  of  effects  may  be  secured  by  a 
judicious  choice  of  material. 

A  sloping  or  hip  roof  is  not  easily  managed  in  fireproof  construction  and 
the  safest  and  most  economical  scheme  is  to  use  a  wood  roof  covered  with 
slate,  asbestos  or  tile  and  sealed  on  the  under  side  with  a  metal  lath  and 
cement  ceiling  built  in  the  same  manner  as  the  walls  of  the  pipe  frame  garage 
described. 

ii 


12 


CONCRETE  TILE  CONSTRUCTION. 

In  various  parts  of  the  country  concrete  hollow  tile  are  to  be  had  which  are 
exceedingly  economical  for  wall  building.  They  are  made  in  various  shapes 
and  sizes  and  may  be  laid  up  by  any  brick  mason  rapidly  and  efficiently.  The 
accompanying  drawing  will  give  some  suggestion  as  to  the  method  of  laying 
these  tile. 


Garage  at  Far  Rockaway,  L.  I.     Stucco  on  Wood  Stud  and  Metal  Lath. 

A  footing  should  be  laid  extending  3  inches  on  each  side  of  the  proposed 
wall  and  from  8  inches  to  10  inches  in  thickness.  This  footing  should  be  car- 
ried down  below  frost  line,  as  in  mass  construction.  The  tiles  which  are  to  be 
had  usually  10  inches  wide  and  8  inches  high,  should  be  laid  on  top  of  this 
tooting  and  carried  up  to  ground  level  or  above.  If  the  load  is  not  too  heavy 
the  smaller  tile — 6"  x  8" — may  be  laid  up  for  the  rest  of  the  wall.  The  tile 
shown  in  the  drawing  at  the  right  are  corner  tile,  with  the  cells  running  ver- 
tically instead  of  horizontally,  and  may  be  used  in  combination  with  the  regu- 
lar wall  tile  for  the  purpose  of  turning  corners  and  working  around  doors  and 
window  jambs.  If  a  two-story  building  is  required  it  is  advisable  to  fill  the 
corner  tiles  with  concrete  and  reinforce  the  piers  thus  formed  with  steel  bars. 
It  will  also  be  found  advisable  to  carry  the  8"  x  10"  tile  up  to  the  level  of  the 
underside  of  the  beams  and  use  the  smaller  tile  for  the  second  story.  A  large 

13 


amount  of  variation  is  possible  with  the  use  of  concrete  tile,  which  will  readily 
suggest  themselves  to  anyone  desiring  to  build  in  this  method.  An  excellent 
fireproof  floor  can  be  made  by  using  the  corner  tile  for  floor  fillers  with  con- 
crete ribs  between  as  indicated  in  the  sketch. 

*Stucco  adheres  readily  to  concrete  tile  walls,  provided  the  wall  is  thor- 


Garage  at  Paterson,  N.  J.     Concrete  Block. 

oughly  wet  when  the  stucco  is  being  applied.  The  stucco,  being  of  the  same 
material  and  having  the  same  coefficient  of  expansion  as  the  tile,  does  not 
crack,  as  is  often  the  case  when  terra  cotta  tile  is  used. 

CONCRETE  BLOCK  WALL  CONSTRUCTION. 

Concrete  blocks  differ  from  concrete  tile  in  the  method  of  manufacture. 
They  are  heavier  and  less  economical  than  tile,  but  may  be  had  in  almost  every 
locality,  and  if  reasonably  well  made  will  do  excellent  service.  They  are  gen- 
erally made  with  rock  face  or  finished  surfaces  and  consequently  do  not  re- 
quire any  surface  treatment  or  stucco.  There  are  many  types  of  blocks  on 
the  market  and  there  is  little  choice  between  them,  although  a  wall  made  of 
two  pieces  is,  as  a  rule,  superior  to  a  wall  made  of  one  piece,  as  these  blocks 
are  not  as  water-tight  as  wet  mixed  concrete,  and  the  wall  is  likely  to  be  damp 


*See  Method  of  Applying  Stucco  Under  Pipe  Frame,  Wire  Lath  and  Stucco. 

15 


i 


if  made  of  one-piece  blocks.  By  using  good  facing  material  and  a  rich 
mixture,  however,  very  good  weatherproof  blocks  can  be  made.  Sills  and 
lintels  may  be  cast  in  wooden  forms  to  fit  window  and  door  openings. 

Concrete  blocks  should  be  laid  as  cut  stone  and  any  good  foreman  is 
competent  to  superintend  the  work. 

Garages  of  this  construction  are  very  often  stuccoed,  as  will  be  seen  by  the 
illustrations. 


Garage  at  Paterson,   N.  J.     Concrete  Block. 

PIPE  WIRE  LATH  AND   STUCCO. 

This  type  of  garage  will  be  found  very  economical  where  material  for  con- 
crete making  is  scarce,  and  where  an  owner  does  not  want  to  go  to  the  ex- 
pense of  solid  construction.  This  construction  consists  of  a  frame  work  of 
pipe  which  can  readily  be  had  and  is  simply  put  together.  The  frame  work 
is  set  in  a  base  of  concrete  and  the  walls  are  covered  with  wire  lath  and  mor- 
tar. The  method  is  simple  and  at  the  same  time  is  applicable  to  variation 
and  decoration  so  as  to  meet  all  practical  requirements  and  make  an  artistic 
structure. 

FOOTING  WALLS. 

Excavate  and  build  a  footing  wall  from  the  surface  of  the  ground  to  below 

17 


a 

2 

rt 

o 


frost  line.  Provide  a  footing  under  the  wall  6  inches  thick  extending  3  inches 
on  either  side.  The  wall  itself  should  be  12  inches  thick,  built  between  suit- 
able plank  forms.  Mix  the  concrete  for  the  wall  and  footing  in  the  propor- 
tion of  i  part  Atlas  Portland  Cement,  2  parts  clean,  coarse  sand  and  5  parts 
gravel  or  broken  stone.  Use  sufficient  water  to  make  a  soft  concrete  and 
puddle  into  place  until  forms  are  thoroughly  filled,  flush  to  the  top. 


Diagram  of  Pipe  Frame  Garage. 


& 

1 


PIPE  DOWELS. 

Before  the  concrete  has  set  imbed  along  the  center  line  of  the  wall  pipe 
dowels  8  inches  long,  threaded  to  receive  the  standards  AA.  If  angles  are 
used  in  place  of  piping,  the  dowels  should  be  large  enough  to  let  the  angles 
down  inside  so  that  cement  mortar  made  of  i  part  Atlas  Portland  Cement  to 
2  parts  of  sand  may  be  poured  down  into  the  dowels  to  hold  the  angles  rigidly 
in  place. 


Garage  at  Scarsdale,  N.  Y.     Concrete  Block. 

The  frame  should,  of  course,  be  laid  out  carefully  on  paper,  and  all  dimen- 
sions determined.  The  local  gasfitter  or  blacksmith  can  then  get  out  main 
structural  parts  and  assemble  them,  only  light  tools  being  necessary  in  either 
case.  For  a  pipe  frame  use  2^-inch  galvanized  uprights,  spaced  not  more 
than  5  feet  on  centers  and  i^-inch  galvanized  horizontals  about  4  feet  apart. 
The  frame,  having  been  set  up,  fastens  on  the  studs  SS  of  s^-inch  by  y4-mch 
flatiron  bent  around  the  horizontal  pipe  and  stretched  well  into  place.  The 
studs  should  not  be  more  than  16  inches  on  centers. 

Metal  lath  should  be  laced  to  the  studs  DD,  tied  on  well  with  No.  16  wire. 
There  are  a  number  of  kinds  of  lath  on  the  market,  some  of  which  are  ribbed 
and  provided  with  clips  or  fasteners  to  take  the  place  of  wiring.  Any  of 
these  will  do,  but  it  is  essential  that  the  ratio  of  opening  in  the  lath  be  large 

21 


as  compared  with  the  area  of  metal.  Wire  mesh,  expanded  metals  and  the 
like  are  best  for  walls  of  this  kind.  Wherever  the  mortar  is  to  be  carried 
around  the  pipe  frame,  as  at  the  edge  of  the  eaves,  carry  the  metal  lath  well 
around  and  wire  firmly. 

In  pipe  frame  construction  three  coats  of  stucco  will  be  required  to  make 
a  good  wall  finishing  about  i^  inches  thick;  two  coats  being  applied  outside 
and  one,  a  finishing  coat,  inside,  a  single  layer  of  metal  being  used. 


Garage  at  Woodmere,  L.  I.    Stucco  on  Wood  Frame  and  Metal  Lath. 

Small  iJ/2-inch  channel  iron  frames,  punched  with  i^-inch  holes  and  pro- 
vided with  bolts,  should  be  set  around  all  door  and  window  openings  to  re- 
ceive a  wooden  buck  to  which  the  door  or  window  frame  may  be  fastened. 
This  should  be  done  before  stucco  is  applied. 

After  the  scratch  coat  (see  specifications  for  stucco,  p.  29)  has  been  applied 
to  roof  and  before  second  coat  is  put  on,  set  2-inch  by  i-inch  beveled  wooden 
strips  running  parallel  with  the  eaves  and  wire  firmly.  The  spacing  will  de- 
pend on  the  kind  of  roofing  to  be  used,  whether  slate,  asbestos,  tiles,  etc. 
After  the  strips  are  set  fill  flush  on  the  top  with  mortar  mixed  2^  parts  sand 
to  one  part  Atlas  Portland  Cement. 

If  desired  many  elaborate  and  beautiful  effects  may  be  secured  by  the 
introduction  of  panels  or  borders  in  tile,  mosaic,  or  even  pebbles  and  field 

23 


bfl 

£ 

ro 
O 


24 


stones.  Frames  of  wood  of  required  outline  and  thickness  should  be  wired  to 
the  lathing  and  the  stucco  work  finished.  After  the  wall  is  hard  remove  the 
wooden  frames  carefully  and  fill  the  panels  by  grouting  in  the  tile  or  other 
ornament,  as  desired. 

Small  angle  iron  may  be  substituted  for  the  pipe  frame,  the  angle  irons 
being  cut  to  the  proper  length,  rivetted  together  and  set  up  in  the  same 
manner  as  for  the  pipe  frame.  The  furring,  metal  lath,  stucco,  etc.,  will  be 
applied  in  the  same  manner  as  described. 


Interior  of  Garage  at  Allentown,  Showing  Wood  Frame  with  Stucco  on  Both  Sides 

of  Metal  Lath. 

WOOD   STUD   FRAME  AND   STUCCO. 

If  a  still  cheaper  method  is  desired,  the  frame  work  of  the  building  may 
be  constructed  of  wood,  2x4  wooden  studs  16  inches  on  centers  with  bridg- 
ing between  being  used  in  place  of  the  pipe  or  angle  iron  frame.  Staple  the 
metal  lath  on  to  the  wooden  studs,  but  have  the  stapling  loose  to  allow  a  cer- 
tain amount  of  play  between  the  lath  and  the  stud. 

Use  two  coats  of  stucco  on  the  outside  and  apply  one  coat  inside  between 
the  2x4  studding.  A  neater  appearing  interior  can  be  had,  and  the  garage 
made  more  fireproof  by  lathing  and  stuccoing  the  interior  in  the  same  manner 
as  the  exterior,  but  in  place  of  making  a  rough  finish  the  finished  coat  should 
be  floated  smooth. 

Detail  drawings  of  a  wood  stud  garage  are  shown  on  page  27  and  a  photo 
on  page  24.  The  cost  of  this  garage  completed  was  $783.80. 

25 


I 

I 

o 


<u 
W) 

2 
cS 


GARAGE  FLOORS. 

Garage  floors  should  be  laid  the  same  as  sidewalks,  detailed  specifications 
for  which  are  given  in  our  book  ''Concrete  Construction  about  the  Home 
and  on  the  Farm,"  copies  of  which  may  be  had  free  upon  request. 

SPECIFICATIONS  FOR  STUCCO. 

The  instructions  given  below  should  be  closely  followed  in  building  any 
of  the  garages  described  in  this  book. 

"Stucco  work  may  be  used  to  cover  wood,  brick,  stone  or  any  other  build- 
ing material,  provided  special  precautions  are  taken  in  preparing  the  surface 
properly  so  that  it  will  adhere  and  not  crack  or  scale  off.  The  work  should 
be  done  by  an  experienced  plasterer. 

"As  a  rule,  two  coats  are  used — the  first,  a  scratch  coat  composed  of  five 
parts  "ATLAS"  Portland  Cement,  twelve  parts  clean,  coarse  sand,  and  three 
parts  slaked  lime  putty  and  a  small  quantity  of  hair;  the  second,  a  finishing 
coat  composed  of  one  part  "ATLAS"  Portland  Cement,  three  or  even  five 
parts  clean,  coarse  sand  and  one  part  slaked  lime  paste.  Should  only  one 
coat  be  desired  the  finishing  coat  is  used.  Some  masons  prefer  a  mortar  in 
which  no  lime  is  used,  but  this  requires  more  time  to  apply. 

"To  apply  stucco  to  brick  or  stone  or  concrete,  clean  the  surface  of  the  wall 
thoroughly,  using  plenty  of  clean  water  so  as  to  soak  the  wall.  If  the  surface 
is  concrete  roughen  it  by  picking  with  a  stone  axe.  Plaster  with  a  i^-inch 
coat  and  finish  the  surface  with  a  wood  float,  or  to  make  a  rough  surface  cover 
the  float  with  burlap.  Protect  the  stucco  work  from  the  sun  and  keep  it  thor- 
oughly wet  for  three  or  four  days ;  the  longer  it  is  kept  wet  the  better. 

"In  using  stucco  on  a  frame  structure,  first  cover  surface  with  two  thick- 
nesses of  roofing  paper.  Next  put  on  furring  strips  about  one  foot  apart, 
and  on  these  fasten  wire  lathing.  (There  are  several  kinds,  any  of  which  are 
good.)  Apply  the  scratch  coat  %  inch  thick  and  press  it  partly  through  the 
openings  in  the  lath,  roughing  the  surface  with  a  stick  or  trowel.  Allow  this 
to  set  well  and  apply  the  finishing  coat  */2  inch  to  i  inch  thick.  This  coat  can 
be  put  on  and  smoothed  with  a  wooden  float,  or  it  can  be  thrown  on  with  a 
trowel  or  large  stiff-fibred  brush,  if  a  spatter-dash  finish  is  desired.  A  pebble- 
dash  finish  may  be  obtained  with  a  final  coat  of  one  part  "ATLAS"  Portland 
Cement,  three  parts  coarse  sand  and  pebbles  not  over  ^4  inch  in  diameter, 
thrown  on  with  a  trowel." 

Quoted  from  copyrighted  book  "Concrete  Construction  about  the  Home 
and  on  the  Farm,"  page  156. 


29 


32 


C/3 


33 


34 


o 


35 


ffl 


CONCRETE 

CONSTRUCTION 

ABOUT  THE  HOME 

AND  ON 

THE  FARM 


THE   RECOGNIZED  TEXT  BOOK 
OF  CEMENT   USERS 


REVISED  EDITION 

1909 


PUBLISHED  BY 

THE  ATLAS   PORTLAND   CEMENT   COMPANY 

30    BROAD     STREET 

NEW   YORK 


Copyright    1905-1907-1909 

by 

THE  ATLAS  PORTLAND  CEMENT  Co. 
30  Broad  Street,  New  York 


All   rights  reserved 


Eighth   Edition 


INDEX. 


PAGE 

Foreword ~ 

Concrete   Construction    (history) g 

"Atlas"  Portland  Cement  (development) Io 


Specifications  for  mixing  and  handling  "Atlas"  Portland  Cement. 

Concrete j  l 

Mortar j : 

Cement : : 

Packing  of  Cement I2 

How  to  Store  Cement 12 

Sand ^ 

How  to  Test  for  a  Clean  Sand 13 

How  to  Wash  Sand 14 

Coarse  Sand 15 

Natural  Mixture  of  Bank  Sand  and  Gravel 15 

Crusher  Screenings 16 

Gravel  or  Broken  Stone  (Coarse  Aggregate) 16 

What  Not  to  Use 16 

Water 17 

Proportions 17 

Forms 19 

Circular  Forms 20 

Tools  and  Apparatus 21 

Measuring 23 

Table  of  Quantity  of  Materials  and  Sizes  of  Measuring  Boxes  for 

Different  Mixes  of  Concrete 23 

Mixing 24 

Placing  Concrete  in  Forms 26 

Placing  Concrete  Under  Water 26 

Surface  Finish 27 

Pure  Cement  Wash 27 

Removing  Surface  Skin  of  Cement  While  Concrete  Is  Green.  ...   27 

Picked  Surface 28 

Plastering 28 

Reinforced  Concrete 28 

Table  for  Designing  Concrete  Beams  and  Slabs 30-31 

Cost  of  Concrete  Work 32 

Table  for  Material  for  i  Cubic  Yard  of  Concrete 33 


SPECIFICATIONS  FOR  MIXING  AND  HANDLING  "ATLAS"  PORTLAND  CEMENT— 
Continued.                                                                                                               PAGE 
Effect  of  External  Agencies  on  Concrete 33 

Fire  Resistance   33 

Water-Tightness 33 

Corrosion  of  Metal  Reinforcement 33 

Sea  Water 33 

Acids 35 

Oils 35 

Alkalies 35 

Freezing 35 

Specifications  for 

Posts 36 

Fence   Posts 36 

Table  of  Quantity  of  Materials  for  Fence  Posts 38 

Cost  of  Fence  Posts 4T 

Corner   Posts 41 

Table  of  Quantity  of  Corner  Posts 41 

Hitching  Posts 4T 

Clothes  Posts 43 

Horse   Blocks 43 

Watering  Troughs 44 

Hog   Troughs 52 

Slop  Tanks •  .  . .   52 

Fertilizer    Tanks 54 

Rain  Leaders 54 

Retaining   Walls 56 

Table  of  Dimensions  of  Retaining  Walls  and  Quantity  of  Ma- 
terials for  Different  Heights  of  Wall 57 

Dams 58 

Table  of  Dimensions  for  Small  Dams  and  Quantity  of  Materials 

for  Different  Heights  of  Dams 59 

Walls 60 

Cellar  and  Basement  Walls 60 

Table  of  Thicknesses  of  Walls  and  Quantity  of  Materials  for  Dif- 
ferent Heights  of  Basement 62 

Walls  above  Cellar  or  Basement 64 

Columns 67 

Steps  and  Stairs 69 

Table  of  Dimensions  of  Stairs 74 

Sidewalks 75 


SPECIFICATIONS  FOR — Continued.                                                                          PAGE 
Table  of  Amount  of  Material  for  Different  Thicknesses  of  Side- 
walks     77 

Curbs  and  Gutters jy 

Barns 81 

Feed  Troughs 81 

Floors 86 

Cellar   Floors 86 

Barn    Floors 86 

Feed  Floors 88 

Runways  from   Stables 89 

Drains 90 

Tile    Drains 91 

Cesspools 94 

Box   Stalls 95 

Ventilation 95 

Hog   Pens 96 

Dairies 98 

Ice   Boxes TOO 

Silos 103 

Table  of  Dimensions  for  Different  Sizes  of  Silos 105 

Hollow  Wall  Silos 112 

Tanks 112 

Square  Tanks 113 

Round    Tanks 114 

Reinforcement  for  Tanks 117 

Table  of  Dimensions  for  Different  Sizes  of  Tanks 117 

Grain  Elevators 117 

Corn   Cribs 1 18 

Cisterns 119 

\Yell  Curbs 121 

Ice   Houses 1 23 

Root    Cellars 1 26 

Mushroom    Cellars 1 29 

Arch    Driveways 130 

Culvert  Driveways 131 

Water  Pipes  Under  Driveways 132 

Hen    Nesting   Houses 132 

Chicken    Houses 1 34 

Green  Houses 1 37 

Concrete  Greenhouse  Tables 139 

Concrete    Greenhouse   Trays H2 


SPECIFICATIONS  FOR — Continued.  PAGE 

Concrete   Flower   Boxes 142 

Hotbed   Frames 144 

Wind  Mill   Foundation 144 

Concrete    Roller 146 

Dance    Pavilion 148 

Piazza. 149 

Lattice 150 

Chimney   Caps 151 

Tree  Surgery 152 

Filling  the  Cavity 153 

Aquarium 1 54 

Concrete  Blocks 1 54 

Stucco  Work — Cement  Plaster,  Spatter  Dash,  Pebble  Dash 156 

Table  of  Coloring  for  Concrete  Finish 1 58 

Concrete  Culverts T  59 

Design  of  5-Foot  Arch  Culverts 160 

Design  of  8-Foot  Arch  Culvert 160 

Table  of  Amount  of  Materials  for  Arch  Culverts 162 

Design  of   ic-Foot  Arch  Culvert 164 


FOREWORD. 

The  development  of  the  American  Portland  Cement  industry  during  the  past 
decade  has  been  one  of  the  marvels  of  the  age,  and  while  Portland  Cement 
Concrete  has  come  to  be  recognized  as  the  ideal  building  material  for  heavy 
work,  comparatively  little  attention  has  been  given  to  its  use  in  the  smaller 
construction  about  the  home  and  on  the  farm.  That  active  interest,  however, 
is  taken  in  this  important  subject  by  the  suburbanite,  the  villager,  and  the 
farmer,  is  evidenced  by  the  large  number  of  letters  of  inquiry  received  by  the 
agricultural  and  technical  journals. 

During  the  past  few  years  the  price  of  lumber  has  advanced  to  almost  pro- 
hibitive figures,  and  it  is  therefore  only  natural  that  a  substitute  material 
which  affords  the  advantages  of  moderate  cost,  durability,  and  beauty  should 
be  looked  upon  with  favor. 

It  is  not  our  purpose  to  enlarge  upon  the  uses  for  which  Portland  Cement  is 
now  considered  standard,  but  rather  to  direct  attention  to  the  economy  of  sup- 
planting wood,  brick,  and  cut  stone  in  divers  ways  by  the  more  durable, 
sightly,  and  sanitary  Portland  Cement  construction. 

In  the  following  pages  we  shall  endeavor  to  point  out,  in  language  free  from 
technical  terms,  some  of  the  uses  for  which  Portland  Cement  Concrete  is  espe- 
cially adapted. 


CONCRETE  CONSTRUCTION. 

Concrete  construction  dates  back  to  the  time  of  the  Romans,  who  secured 
good  results  from  a  mixture  of  slaked  lime,  volcanic  dust,  sand  and  broken 
stone.  Even  this  combination,  crude  in  comparison  with  Portland  Cement 
Concrete,  produced  an  artificial  stone  which  has  stood  the  test  of  nearly  two 
thousand  years,  as  evidenced  by  many  v/orks  in  Rome  which  are  to-day  in  a 
perfect  state  of  preservation. 

"Portland  Cement"  is  an  invention  of  modern  times — its  universal  use  the 
matter  of  a  quarter  of  a  century.  The  honor  of  its  discovery  belongs  to  Joseph 
Aspdin,  of  Leeds,  England,  who  took  out  a  patent  in  1824  for  the  manufacture 
of  "Portland  Cement,"  so  called  because  of  its  resemblance,  in  color,  to  a  then 
popular  limestone  quarried  on  the  Island  of  Portland.  Manufacture  was  begun 
in  1825,  but  progress  was  slow  until  about  1850,  when,  through  improved 
methods  and  general  recognition  of  its  merits  as  a  building  material,  commer- 
cial success  was  assured.  About  this  time  the  manufacture  of  Portland  Cement 
was  taken  up  in  earnest  by  the  French  and  Germans,  and,  by  reason  of  their 
more  scientific  efforts,  both  the  method  of  manufacture  and  quality  of  the  fin- 
ished product  was  greatly  improved.  Portland  Cement  was  first  brought  to 
the  United  States  in  1865.  It  was  first  manufactured  in  this  country  in  1872, 
but  not  until  1896  did  the  annual  domestic  production  reach  the  million-barrel 
mark. 


Wonderful  as  the  development  of  the  general  industry  has  been,  the  growth 
of  the  Atlas  Portland  Cement  Company's  plants  has  been  even  more  so.  Be- 
ginning in  1892  at  Coplay,  Pa.,  with  the  modest  capacity  of  250  barrels  per 
day,  its  production  has  steadily  increased  through  the  construction  of  plants 
Nos.  2,  3,  and  4,  at  Northampton,  Pa.,  and  plants  Nos.  5  and  6,  at  Hannibal, 
Mo.,  until  now  the  productive  capacity  is  more  than  40,000  barrels  each 
twenty-four  hours,  or  approximately  fourteen  million  barrels  per  year. 
This  production  is  greater  than  the  capacity  of  any  other  Portland  Cement 
company  in  the  world.  "ATLAS"  Portland  Cement  is  manufactured  from  the 
finest  raw  materials,  under  expert  supervision  in  every  department  of  the 
works.  It  is  of  the  highest  quality,  being  guaranteed  to  pass  all  usual  and 
customary  specifications,  such  as  the  specifications  of  the  United  States  Gov- 
ernment and  those  of  the  American  Society  for  Testing  Materials,  which  latter 
specifications  have  been  concurred  in  by  The  American  Institute  of  Architects, 
The  American  Engineering  and  Maintenance  of  Way  Association,  and  The 
Association  of  American  Portland  Cement  Manufacturers.  The  quality  of 
eastern  and  western  "ATLAS"  is  identical.  By  virtue  of  its  enormous  produc- 
tion, The  Atlas  Portland  Cement  Company  is  able  to  develop  and  retain  in  its 
service  the  most  skilled  operating  talent  in  the  Portland  Cement  industry, 
which  insures  a  thoroughly  reliable  and  uniform  product. 

"ATLAS"  Portland  Cement  is  guaranteed  to  be  "ALWAYS  UNIFORM." 


10 


Concrete,  which  is  really  an  artificial  stone,  is  made  by  CONCRETE 
mixing  pieces  of  stone,  such  as  broken  granite  or  hard  lime- 
stone, which  may  vary  in  size  from  a  walnut  to  a  hen's  egg, 
with  clean,  coarse  sand  and  first-class  Portland  cement,  using 
enough  water  to  make  a  mushy  mixture  about  like  heavy 
cream. 

The  cement  and  water  make  the  mass  begin  to  stiffen  in 
about  half  an  hour,  and  in  from  10  to  24  hours  it  becomes  hard 
enough  so  that  an  impression  cannot  readily  be  made  by  press- 
ing on  it  with  the  thumb.  In  a  month's  time  the  entire  mass 
becomes  one  hard  stone. 

Conglomerate  or  pudding  stone  in  nature  is  really  a  natural 
cement  concrete,  the  large  and  small  particles  of  pieces  of  stone 
and  sand  being  cemented  together  in  the  course  of  ages  in  a 
similar  way  to  that  by  which  cement  is  made. 

Where  a  very  strong  mortar  is  required  for  laying  brick  or  MORTAR 

stone,  "ATLAS"  Portland  cement  may  be  mixed  with  sand  in 
proportions  one  part  "ATLAS"  cement  to  two  and  one-half 
parts  sand.  A  characteristic  of  "ATLAS"  Portland  Cement  is 
that  it  gives  an  especially  greasy  mortar. 

A  mortar  nearly  as  strong  as  the  above,  and  which  works 
still  better  under  the  trowel,  can  be  made  by  mixing  one  bag 
"ATLAS"  Portland  cement  with  one  barrel  of  clean  sand  and 
one-half  pail  of  lime  putty.  The  lime  putty  is  made  by  thor- 
oughly slaking  quick  lime.  The  longer  the  time  the  putty  can 
stand  before  using  the  better  it  is.  It  must  never  be  used  when 
hot  or  until  the  lime  is  thoroughly  slaked.  When  laying  up 
brick  and  stone  with  any  kind  of  mortar  they  must  be  thor- 
oughly wet. 

Always  use  the  best  Portland  cement  obtainable.  Natural  CEMENT 

cement  is  not  suitable  for  concrete.  Whatever  the  kind  of 
cement,  unless  it  is  of  first-class  quality,  it  may  give  trouble 
by  not  setting  up  and  hardening  properly. 

Portland  cement  is  manufactured  from  a  mixture  of  two 
materials,  one  of  them  a  rock  like  limestone,  or  a  softer  mate- 
rial like  chalk,  which  is  nearly  pure  lime,  and  another  material 
like  shale,  which  is  a  hardened  clay  or  else  clay  itself.  In 
other  words,  there  must  be  one  material  which  is  largely  lime 
and  another  material  which  is  largely  clay,  and  these  two  must 

ii 


CEMENT  be  mixed  in  very  exact  proportions  determined  by  chemical 

(Cont'd)  tests,  the  proportions  of  the  two  being  changed  every  few 

hours,  if  necessary,  to  allow  for  the  variation  in  the  chemical 
composition  of  the  materials. 

"ATLAS"  PORTLAND  CEMENT  then  is  made  by  quar- 
rying each  of  these  two  materials,  crushing  them  separately, 
mixing  them  in  the  exact  proportions,  and  grinding  them  to  a 
very  fine  powder.  This  powder  is  fed  into  long  rotary  kilns, 
which  are  iron  tubes  about  5  or  6  feet  in  diameter,  lined  with 
fire  brick  and  over  100  feet  long.  Powdered  coal  is  also  fed  into 
the  kilns  with  the  ground  rock  and  burned  at  a  temperature  of 
about  3000  degrees  Fahrenheit,  a  temperature  higher  than  that 
needed  to  melt  iron  to  a  liquid,  and  there  is  formed  what  is 
called  cement  clinker,  a  kind  of  dark,  porous  stone  which  looks 
like  lava. 

After  leaving  the  kiln,  the  clinker  is  cooled,  crushed  and 
ground  again  to  a  still  finer  powder,  so  fine,  in  fact,  that  most 
of  the  particles  are  less  than  1/200  of  an  inch  in  size,  and  this 
grinding  brings  it  back  to  the  very  light  gray  color  character- 
istic of  "ATLAS"  Portland  Cement. 

It  is  now  placed  in  storage  tanks  or  stock  houses  where  it 
remains  for  a  while  to  season  before  it  is  put  into  bags  or 
barrels  and  shipped.  The  barrels  weigh  400  pounds  gross,  or 
376  pounds  net.  When  shipped  in  bags,  the  weight  is  94 
pounds  per  bag,  four  bags  being  equal  to  one  barrel. 

At  the  "ATLAS"  plants,  from  the  time  the  rock  is  taken 
from  the  quarry  until  it  is  packed  in  barrels  or  bags,  all  of 
the  work  is  done  by  machinery,  and  a  thorough  chemical 
mixture  takes  place  regulated  by  the  experienced  chemists  in 
charge  of  the  work. 

PACKING  OF  CEMENT.  Portland  cement  may  be  obtained 
in  paper  bags,  cloth  sacks  or  wooden  barrels.  The  most  con- 
venient form  for  most  users  is  the  cloth  sack.  These  sacks 
can  be  returned  to  the  dealer  from  whom  the  cement  was 
purchased  and  a  rebate  obtained  for  them  if  they  are  kept  dry 
and  untorn. 

HOW  TO  STORE  CEMENT.  Portland  cement  must  be 
stored  in  a  dry  place,  that  is,  in  a  barn  or  shed,  for  dampness 
is  the  only  element  which  will  injure  its  quality.  The  cement 
will  become  lumpy  and  even  form  a  solid  mass  when  kept  in  a 
damp  place,  and  when  in  this  condition  it  should  not  be  used. 


12 


All  lumps  which  do  not  crumble  at  the  lightest  blow  should  be 
thrown  out. 

Cement  stored  in  a  building  must  not  be  placed  on  the 
bare  ground.  Make  a  platform  which  is  at  least  6  inches 
above  the  ground,  and  store  the  cement  on  this  platform.  If 
the  building  has  a  concrete  floor  it  is  advisable  to  cover  the 
floor  with  planking  upon  which  to  place  the  cement. 

Sand,  crushed  stone  or  gravel  screenings  passing  when  dry        SAND    (Fine 
a  screen  having  %-inch  diameter  holes  is  called  the  fine  aggre-  Aggregate) 

gate.  Sand  should  be  (i)  clean,  that  is,  free  from  dirt  like 
vegetable,  loam,  and  (2)  coarse. 

If  the  sand  contains  vegetable  matter,  it  is  difficult  to  tell 
whether  the  sand  is  good,  because  a  very  small  quantity — a 
fraction  of  one  per  cent. — may  sometimes  prevent  the  con- 
crete from  hardening.  When  the  job  is  small,  however,  an 
approximate  idea  of  the  quality  may  be  obtained  by  exam- 
ining the  sand  in  the  bank  and  making  up  a  specimen  of 
concrete  on  the  job  as  described  below.  The  ordinary  plan  of 
taking  a  little  sand  in  the  palm  of  one  hand  and  rubbing  it 
with  the  fingers  of  the  other  to  see  if  it  discolors  is  of  little 
value,  and  little  can  be  learned  from  dropping  sand  in  water, 
because  it  is  not  so  much  the  quantity  as  the  kind  of  impurity 
that  counts. 

HOW  TO  TEST  FOR  A  CLEAN  SAND.  Two  rough  tests 
are  as  follows :  (a)  Pick  up  a  double  handful  of  moist  sand 
from  the  bank,  open  the  hands,  holding  them  with  the  thumbs 
up,  and  rub  the  sand  lightly  between  the  hands,  keeping  them 
about  */2  inch  apart,  allowing  the  sand  to  slip  quickly  between 
them.  Repeat  this  operation  five  or  six  times,  then  rub  the 
hands  lightly  together  so  as  to  remove  the  fine  grains  of  sand 
which  adhere  to  them,  and  examine  to  see  whether  or  not  a 
thin  film  of  sticky  matter  adheres  to  the  fingers;  if  so,  do  not 
use  the  sand,  for  it  contains  loam.  A  further  test  is  to  scrape 
some  of  this  matter  from  the  fingers  on  the  end  of  a  penknife 
and  take  a  little  of  it  between  the  teeth.  If  it  does  not  feel 
gritty  or  sharp  it  indicates  vegetable  loam,  which  is  bad.  Do 
not  use  this  sand,  or  if  no  other  can  be  obtained  test  it  further 
to  make  sure  that  there  is  not  sufficient  loam  present  to  prevent 
the  cement  from  getting  thoroughly  hard. 

13 


SAND     (Fine 
Aggregate) 
(Confd.) 


The  sand  for  the  test  given  above  must  be  moist,  just  as  it 
comes  from  the  bank.  When  dry  the  dirt  will  not  stick  to  the 
fingers,  hence  this  test  cannot  be  used.  Some  idea  can  be 
obtained,  however,  by  the  appearance  of  the  sand,  even  if  it 
is  dry.  If  it  looks  "dead,"  an  appearance  which  is  caused 
by  the  particles  of  dirt  sticking  in  little  lumps  to  the  grains 
of  sand,  sometimes  also  making  the  grains  of  sand  stick  to- 
gether in  little  bunches  when  picked  up,  it  is  almost  a  sure 
sign  of  vegetable  matter,  and  the  sand  should  not  be  used. 
Fine  roots  in  a  sand  will  also  indicate  the  presence  of  vegetable 
matter. 

(b)  Make  up  two  blocks  of  concrete,  each  about  6  inches 
square  and  6  inches  thick,  using  the  same  cement  and  the 
same  sand  and  gravel  or  stone  as  will  be  used  in  the  structure 
to  be  built,  and  mixing  them  in  the  same  proportions  and  of 
the  same  consistency.  Keep  one  block  in  the  air  out  of  doors 
for  7  days  and  the  other  in  a  fairly  warm  room. 

The  specimen  in  the  warm  room  should  set  so  that  on  the 
following  day  it  will  bear  the  pressure  of  the  thumb  without 
indentation,  and  it  should  also  begin  to  whiten  out  at  this 
early  period.  The  specimen  out  of  doors  should  be  hard 
enough  to  remove  from  the  molds  in  24  hours  in  ordinary  mild 
weather,  or  48  hours  in  cold,  damp  weather.  At  the  end  of  a 
week  test  both  blocks  by  hitting  them  with  a  hammer.  If  the 
hammer  does  not  dent  them  under  light  blows,  such  as  would 
be  used  for  driving  tacks,  and  the  blocks  sound  hard  and  are 
not  broken  under  medium  blows,  the  sand  as  a  general  rule 
can  be  used. 

HOW  TO  WASH  SAND.  Sand  cannot  be  washed  simply  by 
wetting  the  pile  of  sand  with  a  hose,  for  this  only  washes  or 
transfers  the  dirt  to  a  lower  part  of  the  pile.  Sand,  provided 
it  is  not  too  fine,  can  be  satisfactorily  washed,  however,  by 
making  a  washing  trough,  as  shown  in  Fig.  i.  For  sands  a 
screen  with  30  meshes  to  the  linear  inch  is  necessary  to  prevent 
the  good  particles  from  passing  through  it.  This  must  be  sup- 
ported by  cleats  placed  quite  near  together,  or  it  will  break 
through.  The  sand  is  shoveled  on  to  the  upper  end  of  the 
trough  by  one  man,  while  another  one  can  wash  it  with  a  hose. 
The  flow  of  water  will  wash  the  sand  down  the  incline,  and  as 
the  sand  and  water  pass  over  the  screen  the  dirty  water  will 


drain  off  through  the  screen,  leaving  the  clean  sand  for  use. 
By  this  arrangement  the  dirt  which  is  washed  out  cannot  in 
any  way  get  mixed  with  the  clean  sand 


SAND       (Fine 

Aggregate  ) 

(Cont'd  ) 


Fine.  me.<sh  screen 


Trough  fo  run  off "• dirty  wafer 
Trough  fo  6&  //nee/  wM  farredf>a/ 

Fig.  i.    Washing  Trough  for  Sand  or  Gravel. 

COARSE  SAND.  Sand  should  be  coarse.  By  this  we  mean 
that  a  large  proportion  of  the  grains  should  measure  1/32  to  % 
inch  in  diameter,  and  should  the  grains  run  up  to  %  mcn  the 
strength  of  the  mortar  is  increased.  Fine  sand,  even  if  clean, 
makes  a  poor  mortar  or  concrete,  and,  if  its  use  is  unavoidable, 
an  additional  proportion  of  cement  must  be  used  with  it  to 
thoroughly  coat  the  grains. 

If  the  sand  is  very  fine  a  mortar  or  concrete  made  from  it 
will  not  be  strong.  Sometimes  fine  sand  must  be  used  because 
no  other  can  be  obtained,  but  in  such  a  case,  double  the  amount 
of  cement  may  be  required.  For  example,  instead  of  using  a 
concrete  one  part  cement  to  two  parts  sand  to  four  parts  stone, 
a  concrete  one  part  cement  to  one  part  sand  to  two  parts  stone 
may  be  used. 

NATURAL  MIXTURES  OF  BANK  SAND  AND  GRAVEL. 
Very  often  the  sand  and  gravel  found  in  a  bank  are  used  by 
inexperienced  people  just  as  it  is  found  without  regard  to  the 
proportions  of  the  two  materials.  This  may  be  all  right  in 
some  cases,  but  generally  there  is  too  much  sand  for  the 
gravel  or  stone,  so  that  the  resulting  concrete  is  not  nearly  as 
strong  as  it  would  be  if  the  proportions  between  the  sand  and 

15 


gravel  were  right.  It  is  better  then  to  screen  the  sand  from 
the  gravel  through  a  %-inch  sieve,  and  then  mix  the  materials 
in  the  right  proportions,  using  generally  about  half  as  much 
sand  as  stone.  By  so  doing  a  leaner  mix  can  be  used  than 
where  the  sand  and  gravel  are  taken  from  the  bank  direct. 
The  cost  of  the  cement  saved  will  more  than  pay  for  the  extra 
labor  required  to  screen  the  material.  For  example:  Using 
even  a  very  good  gravel  bank,  a  mixture  one  part  cement  to 
four  parts  natural  gravel  must  be  employed  instead  of  one 
part  cement  to  two  parts  sand  to  four  parts  of  screened  gravel. 
So  much  more  cement  is  thus  required  with  the  natural  gravel 
that  a  saving  of  one  bag  of  cement  in  every  seven  is  made  by 
screening  and  remixing  in  the  right  proportion. 
CRUSHER  SCREENINGS.  Screenings  from  broken  stone 
make  an  excellent  fine  aggregate,  which  can  be  substituted  for 
sand  unless  the  stone  is  very  soft,  shelly  or  contains  a  large 
percentage  of  mica. 


GRAVEL  OR  Gravel  or  broken  stone  forms  the  largest  part  of  the  mass 

RD^^I^  F  I\I 

STONE    (Coarse  °*  a  g°°d  concrete,  and  is  called  the  coarse  aggregate.     If  the 
Aggregate^  concrete  is  to  be  used  simply  for  filling,  or  in  a  low  wall  against 

which  nothing  is  to  be  piled,  clean  cinders,  screened  to  remove 
the  dust,  may  sometimes  be  used  for  the  coarse  aggregate. 
The  concrete  made  from  them,  however,  is  not  strong  and  is 
very  porous.  Slag  or  broken  brick  are  sometimes  used  for  the 
coarse  aggregate. 

The  size  of  the  stone  is  best  graded  from  fine  particles 
about  ^4  inch  diameter  up  to  the  coarser.  The  largest  size 
pieces  may  be  2^4  inches  where  a  foundation  or  a  wall  12 
inches  thick  or  over  is  being  built,  while  for  thin  walls  and 
where  reinforcement  is  used  the  largest  particles  had  best  be 
about  f4-inch  size. 

With  gravel  the  danger  is  apt  to  lie  in  the  grains  being 
coated  with  clay  or  vegetable  matter  which  prevents  the 
cement  from  sticking  to  them,  and  hence  a  very  weak  concrete 
results.  The  method  for  washing  gravel  should  be  the  same 
as  that  described  for  sand  (see  page  14)  and  shown  in  Fig.  i. 
The  screen  when  washing  the  gravel  should  have  openings  % 
inch  square. 

16 


WHAT  NOT  TO  USE.  Do  not  use  dirty  stone  or  gravel  in 
any  case.  Avoid  soft  sandstones,  soft  freestones,  soft  lime- 
stones, slate  and  shale. 

The  water  used  for  concrete  must  be  clean.     It  should  not  WATER 

be  taken  from  a  stream  or  pond  into  which  any  waste  from 
chemical  mills,  material  from  barns,  as  manure,  or  other  refuse, 
is  dumped.  If  the  water  runs  through  alkali  soil  or  contains 
vegetable  matter  it  is  best  to  make  up  a  block  of  concrete, 
using  this  water,  and  see  whether  the  cement  sets  properly. 
Do  not  use  sea  water. 

Concrete  is  composed  of  a  certain  amount  or  proportion  of  PROPORTIONS 
cement,  a  larger  amount  of  sand,  and  a  still  larger  amount  of 
stone.  The  fixing  of  the  quantities  of  each  of  these  materials 
is  called  proportioning.  The  proportions  for  a  mix  of  concrete 
given,  for  instance,  one  part  of  cement  to  two  parts  of  sand  to 
four  parts  of  stone  or  gravel,  are  written  i  :2  14,  and  this  means 
that  one  cubic  foot  of  packed  cement  is  to  be  mixed  with  two 
cubic  feet  of  sand  and  with  four  cubic  feet  of  loose  stone. 

For  ordinary  work  use  twice  as  much  coarse  aggregate 
(that  is,  gravel  or  stone)  as  fine  aggregate  (that  is,  sand). 

If  gravel  from  a  natural  bank  is  used  without  screening, 
use  the  same  proportion  called  for  of  the  coarse  aggregate; 
that  is,  if  the  specifications  call  for  proportions  1 12  14,  as  given 
above,  use  for  unscreened  gravel  (provided  it  contains  quite  a 
large  quantity  of  stone)  one  part  cement  to  four  parts 
unscreened  gravel. 

If  when  placing  concrete  with  the  proportions  specified,  a 
wall  shows  many  voids  or  pockets  of  stone,  use  a  little  more 
sand  and  a  little  less  stone  than  called  for.  If,  on  the  other 
hand,  when  placing,  a  lot  of  mortar  rises  to  the  top,  use  less 
sand  and  more  stone  in  the  next  batch. 

In  calculating  the  amount  of  each  of  the  materials  to  use 
for  any  piece  of  work,  do  not  make  the  mistake  so  often  made 
by  the  inexperienced  that  one  barrel  of  cement,  two  barrels  of 
sand  and  four  barrels  of  stone  will  make  seven  barrels  of 
concrete.  As  previously  stated,  the  sand  fills  in  the  voids 
between  the  stones,  while  the  cement  fills  the  voids  between 
the  grains  of  sand,  and  therefore  the  total  quantity  of  concrete 
will  be  slightly  in  excess  of  the  original  quantity  of  stone. 
This  point  is  very  clearly  shown  in  Fig.  2. 

17 


.1  i 


SAND 


GRADED  STONE 


MIXTURE 


Fig.  2.     Diagram  Illustrating  Measurement  of  Dry  Materials 
and  the  Mixture.* 


PROPORTIONS 
(Cont'd) 


The  following  quotation  from  Concrete,  Plain  and  Rein- 
forced,* by  the  well-known  authorities,  Taylor  and  Thompson, 
is  printed  as  a  guide  to  those  who  wish  to  build  any  concrete 
structure  for  which  specific  instructions  are  not  given  in  the 
following  pages. 

"As  a  rough  guide  to  the  selection  of  materials  for  various 
classes  of  work,  we  may  take  four  proportions  which  differ 
from  each  other  simply  in  the  relative  quantity  of  cement." 

"(a)  A  Rich  Mixture  for  columns  and  other  structural 
parts  subjected  to  high  stresses  or  requiring  exceptional  water- 
tightness:  Proportions— 1:1^:3;  that  is,  one  barrel  (4  bags) 
packed  Portland  cement  to  one  and  one-half  barrels  (5.7  cubic 
feet)  loose  sand  to  three  barrels  (11.4  cubic  feet)  loose  gravel 
or  broken  stone. 

"(b)  A  Standard  Mixture  for  reinforced  floors,  beams  and 
columns,  for  arches,  for  reinforced  engine  or  machine  founda- 
tions subject  to  vibrations,  for  tanks,  sewers,  conduits  and  other 
water-tight  work:  Proportions — 1:2:4;  that  is,  one  barrel 
(4  bags)  packed  Portland  cement  to  two  barrels  (7.6  cubic  feet) 
loose  sand  to  four  barrels  (15.2  cubic  feet)  loose  gravel  or 
broken  stone. 

"(c)  A  Medium  Mixture  for  ordinary  machine  foundations, 
retaining  walls,  abutments,  piers,  thin  foundation  walls,  building 
walls,  ordinary  floors,  sidewalks  and  sewers  with  heavy  walls: 
Proportions — 1:2^:5;  that  is,  one  barrel  (4  bags)  packed 
Portland  cement  to  two  and  one-half  barrels  (9.5  cubic  feet) 
loose  sand  to  five  barrels  (19  cubic  feet)  loose  gravel  or  broken 
stone. 

"(d)  A  Lean  Mixture  for  unimportant  work  in  masses,  for 
heavy  walls,  for  large  foundations  supporting  a  stationary  load 
and  for  backing  for  stone  masonry:  Proportions — i  13  :6;  that 
is,  one  barrel  (4  bags)  packed  Portland  cement  to  three  barrels 
(11.4  cubic  feet)  loose  sand  to  six  barrels  (22.8  cubic  feet)  looss 
gravel  or  broken  stone." 

Taken  by  permission  from  Taylor  &  Thompson's  "Concrete  Plain 
and  Reinforced,"  John  Wiley  &  Sons,  New  York,  publishers. 

18 


Green  timber  is  preferable,  for,  if  seasoned,  it  is  likely  to 
swell  and  warp  when  brought  in  contact  with  moisture  from 
the  concrete.  White  pine  is  best,  but  fir,  yellow  pine  or  spruce 
are  also  suitable.  If  a  smooth  surface  is  desired,  the  form 
boards  or  planks  next  to  the  concrete  must  be  planed  and  the 
edges  tongued  and  grooved  or  beveled.  Grease  the  inside  of 
forms  with  either  soap,  linseed  oil,  mixed  lard  and  kerosene,  or 
crude  oil,  that  is,  petroleum,  otherwise  particles  of  concrete 
will  stick  to  the  forms  when  they  are  removed,  thus  giving  an 
unnecessarily  rough  surface  to  the  face  of  the  concrete.  Forms 


FORMS 


Fig.  3.    Section  of  Forms  Showing  Method  of  Holding  Sides  of  Forms. 

should  not  be  greased  when  it  is  intended  to  plaster  the  surface 
of  the  concrete,  but  should  be  thoroughly  wet  immediately 
before  placing  the  concrete. 

Lay  the  sheathing  or  form  boards  horizontally.  These 
may  be  of  i-inch,  i^-inch  or  2-inch  lumber,  the  distance  apart 
of  the  studding  being  governed  by  the  thickness  of  sheathing 
selected.  Place  the  studs  not  more  than  2  feet  apart  for  i-inch 
sheathing,  nor  more  than  5  feet  apart  for  2-inch  sheathing. 
They  should  be  securely  braced  to  withstand  the  pressure  of 
the  soft  concrete,  also  of  the  ramming  and  tamping.  In  build- 
ing forms  do  not  drive  the  nails  all  the  way  home.  Leave  the 
heads  out  so  that  it  is  possible  to  draw  them  with  a  claw 
hammer.  The  less  hammering  done  around  green  concrete 


the  better.  Avoid  cracks  in  forms  into  which  the  mortar  will 
force  itself  and  form  "fins"  on  the  surface  of  the  work. 

The  length  of  time  the  forms  should  be  left  in  place  varies 
with  conditions.  Where  no  pressure  is  brought  to  bear  on  the 
concrete,  forms  can  be  removed  within  one-half  to  two  days,  or 
as  soon  as  the  concrete  will  withstand  the  pressure  of  the 
thumb  without  indentation.  On  very  small  work,  like  drain 
tile,  two  to  four  hours  is  sufficient  time,  provided  it  is  carefully 
handled  and  left  in  place  until  thoroughly  hard.  On  large  and 
important  walls  one  to  three  days  are  generally  required,  and 
if  any  water  or  earth  pressure  comes  against  the  walls  the 
forms  should  be  left  in  place  from  three  to  four  weeks.  Slab 
forms  can  be  removed  in  about  one  week,  but  the  supporting 
posts  under  any  beams  and  slabs  must  not  be  touched  for  a 
month  after  laying  the  concrete. 

Concrete  forms  are  kept  from  separating  or  bulging  either 
by  using  bolts  or  by  wiring.  Bolts  as  a  general  rule  are  more 
satisfactory  on  large  work  than  wire,  but  as  they  cannot 
always  be  conveniently  obtained,  wires  are  used  extensively. 
In  Fig.  3  are  sketched  both  methods  for  holding  side  forms 
together.  The  spacers  are  only  placed  between  the  forms  to 
hold  them  the  proper  distance  apart,  and  must  be  removed 
after  some  of  the  concrete  is  placed.  Where  wires  are  used, 
the  forms  are  drawn  together  by  twisting,  as  shown  in  the 
figure.  This  is  done  with  a  large  nail  or  a  hammer  handle. 

CIRCULAR  For  a  round  structure  two  sets  of  circular  forms  are  usually 

FORMS  needed,  namely,  inner  and  outer  forms,  "A"  and  "B,"  Fig.  5. 

Both  of  these  come  into  use  when  building  a  silo  or  other  struc- 
ture having  a  thin  wall,  but  in  the  case  of  a  solid  column  only 
the  outer  form  is  necessary.  Both  inner  and  outer  forms  are 
made  practically  the  same,  except  that  the  radius  of  the  outer 
one  is  of  necessity  greater  than  that  of  the  inner  because  of  the 
thickness  of  the  walls  between  the  two  forms. 

A  simple  method  of  drawing  the  circle  for  the  outer  form  is 
as  follows:  Take  a  piece  of  string,  attach  one  end  to  a  long 
spike,  marked  "A,"  Fig.  4,  and  stick  it  into  the  ground. 
Measure  off  on  the  string  one-half  the  diameter  of  the  circle 
desired,  tie  a  knot,  through  which  force  a  nail  (marked  "B," 
Fig.  4),  and,  keeping  the  string  stretched  between  these  two 
points,  draw  a  continuous  line.  Lay  the  boards  around  the 
line  just  made,  nail  them  together  firmly  and  then  mark  the 

20 


circle  out  on  them  and  saw  to  the  line.    After  making  two  or  CIRCULAR 

more  forms,  place  them  at  equal  distances  apart,  and  put  on  FORMS  (Cont'd) 
the  sideboards  in  the  manner  shown  in  Fig.  5.     These  boards 
are  called  "Lagging." 


f^orn. 


B 


3ecfiort3  of 
C/rcufor 


Fig.  4.   Laying  Out  Circular  Forms, 


fcrfrcaf  Secfton. 

Fig.  5.   Circular  Forms. 


The  quantity  of  tools  will,  of  course,  vary  with  the  size  of 
the  gang  of  men.  The  following  schedule  is  based  on  a  small 
gang  of  two  or  three  men,  making  concrete  by  hand: 


TOOLS  AND 
APPARATUS 


Concrete  Wheelbarrow. 


Square  Pointed  Shovel 


Three  No.  3  square-pointed  shovels. 

Two  wheelbarrows  (iron  wheelbarrows  the  best). 

One  tamper,  a  piece  of  2  x  4-inch  joist  is  sufficient. 

One  garden  spade  or  spading  tool. 

One  water  barrel. 

Three  water  buckets. 


One  sand  screen,  %-inch  or  %-mch  mesh,  for  screening 
sand  from  the  gravel. 

One  measuring  box  (see  Fig.  6). 

One  mixing  platform  about  10  feet  square  built  so  substan- 
tially that  it  can  be  moved  without  coming  to  pieces,  having  a 
2  x  3-inch  strip  around  the  edge  to  prevent  the  waste  of  mate- 
rials and  water.  This  platform  can  be  made  of  i-inch  stuff, 
resting  on  joists  about  2  feet  apart,  provided  it  is  stiffened  by 
being  tongued  and  grooved. 


Fig.  6.    Measuring  Box  for  Sand  and  Gravel.* 

Concrete  should  be  mixed  as  near  the  place  where  it  is  to  be 
used  as  practicable,  so  as  to  avoid  delay  in  getting  it  into  place. 
If  left  standing  any  length  of  time  it  will  set  and  become  use- 
less. To  avoid  this,  mix  small  batches  at  a  time,  using  on  a 
small  job  not  more  than  a  half  barrel  or  two  bags  of  cement  to 
the  batch.  Should  the  cement  take  its  initial  set,  i.  e.,  begin  to 
harden,  before  being  placed  in  the  forms,  so  that  it  lumps: 
when  retempered,  discard  it,  as  the  hardening  qualities  of 
cement  are  affected  if  disturbed  after  it  has  begun  to  set. 

If  sand  or  gravel  require  washing,  add  to  the  above  list  of 
tools  and  apparatus : 

One  washing  screen  for  sand  with  30  meshes  to  the  linear 
inch. 

One  washing  screen  for  gravel  with  ^4-inch  meshes. 

*See  footnote,  page  18. 

22 


Too  much  attention  cannot  be  paid  to  this  important  part 
of  concrete  making.  The  best  and  most  convenient  way  to 
measure  the  sand  and  stone  is  to  make  a  measuring  box  or 
frame  as  shown  in  Fig.  6. 

The  inside  dimensions  of  the  box  for  different  mixes  of 
concrete  are  given  in  the  table  below,  the  size  of  the  box  being 

QUANTITY  OF  MATERIALS  AND  SIZES  OF  MEASURING  BOXES. 


MEASURING 


.(j 

«   rn 

Con- 

Size of 

Mix 

C    &> 

C   oi 

Sand 

Gravel 

crete 

Measuring 

r^W 

Made, 

Box 

LJ 

Cu.  Ft. 

Lgtb.Dpth.Wdth. 

1:U:3 

2 

2.8  cu.  ft.  or    f  bbl. 

5.6cu.  ft.  or  l^bbl. 

7.0 

3'0"x2'0"xlO" 

1-2    :4 

2 

3.8  cu.  ft.  or  1    bbl. 

7.6cu.  ft.  or  2    bbl. 

9.0 

4'0"x2'4"xlO" 

1:2^:5 

2 

4.8  cu.  ft.  or  libbl. 

9.6  cu.  ft.  or  2*  bbl. 

10.9 

4'6"x2'2"xl2" 

1:3    :6 

2 

5.8  cu.  ft.  or  Hbbl. 

11.6  cu.  ft.  or  3    bbl. 

12.8 

4'6"x2'  7"xl2" 

Note.- — A  cement  barrel  holds  3.8  cubic  feet. 

based  on  a  two-bag  batch  of  concrete;  that  is,  using  two  bags 
"ATLAS"  Portland  Cement  to  each  batch.  The  use  of  the  box 
or  frame  for  measuring  can  be  best  illustrated  by  the  following 
example :  Assume  a  1 12  14  mix.  From  the  table  a  measuring 
frame  or  box,  10  inches  high  by  2  feet  3  inches  by  4  feet  inside 
dimensions,  must  be  made.  Lay  this  box  on  the  mixing  plat- 
form, fill  it  exactly  half  full  of  sand,  up  to  a  mark  previously 
made  all  around  it,  and  level  off  the  sand  to  make  sure  that  the 
sand  just  fills  half  the  frame,  and  then  raise  the  measuring 
frame.  Dump  two  bags  of  cement  on  the  sand  and  mix  it  as 
described  under  "Mixing,"  on  page  24.  Even  off  the  mixed 
cement  and  sand,  place  the  measuring  box  on  top  of  it  and  fill 
the  frame  with  stone  level  with  the  top.  Level  off  the  stone 
carefully,  raise  the  measuring  box  and  the  correct  amount  of 
stone  is  ready  to  be  mixed  with  the  cement  and  sand. 

Another  way  to  measure  the  sand  and  stone  is  by  using  a 
wheelbarrow.  To  determine  the  capacity  of  the  wheelbarrow, 
dump  into  it  one  or  two  bags  of  cement  and  see  how  much  of 
the  wheelbarrow  is  filled;  taking  this  as  a  unit,  measure  the 
sand  and  stone  accordingly,  using  perhaps  a  little  less  of  the 
sand  and  stone  than  would  be  indicated  by  the  cement  measure 
considered  as  one  part.  This  method  is  not  nearly  so  accurate 
as  the  first  one,  and  if  used  the  barrow  should  be  filled  with 
the  cement  two  or  three  times  a  day  to  keep  the  eye  trained. 


23 


MIXING  An  essential  to  thorough  mixing  is  a  flat  water-tight  plat- 

form, a  convenient  size  being  about  10  feet  square,  the  boards 
forming  which  must  be  laid  with  tight  joints  to  prevent  the 
cement  and  water  from  running  through  while  mixing.  If  these 
boards  are  planed  off  on  top  it  will  make  the  shoveling  easier. 
The  operation  of  mixing  the  materials  for  concrete  is  as 
follows:  Measure  the  sand  and  spread  it  in  a  layer  of  even 
depth  as  shown  in  Fig.  7.  Place  the  cement  on  top  of  the 
sand.  First  turn  these  two  materials  toward  the  center  of 
the  board  (see  Fig.  7)  and  then  turn  them  twice  more  or  until 
they  are  thoroughly  mixed  together,  as  indicated  by  a  uniform 


IMPROVISED  MIXING  PLATFORM  AND  TOOLS  USED  ON  SMALL  JOB  AT  COLUMBIA,  MO. 

color.  Next  wet  the  stone,  throw  it  on  top  of  the  mixed 
cement  and  sand  and  turn  the  whole  mass  at  least  three  times, 
water  being  slowly  poured  on  during  the  first  turning,  the 
quantity  varying  according  to  the  nature  of  the  work.  In 
general,  add  sufficient  water  to  give  a  "mushy"  mixture  just  too 
soft  to  bear  the  weight  of  a  man  when  in  place.  Pails  are  most 
convenient  for  measuring  the  water,  and  enough  pailfuls 
should  be  provided  in  advance  for  wetting  an  entire  batch. 
Do  not  use  a  hoe.  In  turning  the  concrete  use  square-pointed 

24 


10  Ft. 


Fig.  7.    Position  of  Piles  of  Cement  and  Sand  During  Mixing/ 


/Oft. 


Wet  and  turn  6  f//r?es 


Fig.  8.    Position  of  Materials  During  Mixing  of  Concrete. 
*See  footnote,  page  18. 

25 


PLACING 
CONCRETE 

IN 
FORMS 


PLACING 
CONCRETE 
UNDER 
WATER 


shovels.  Push  the  shovel  along  the  boards  under  the  mass, 
lift  it,  then  turning  the  shovel  carefully  over  deposit  the  mate- 
rial with  a  spreading  motion.  Concrete  mixing  machines 
should  be  used  on  large  jobs  as  a  matter  of  economy. 

Place  the  concrete  in  forms  in  layers  about  6  to  12  inches 
deep  and  tamp  lightly  with  a  rammer  or  puddle  with  a  piece  of 
2  by  4-inch  joint  until  the  water  flushes  to  the  top.  Note  that 
the  concrete  must  be  well  rammed  and  spaded  to  avoid  pockets 
of  stone  forming  in  the  concrete. 

The  method  of  obtaining  a  smooth  face  on  concrete  fre- 
quently adopted  is  as  follows:  Thrust  a  spade  or  thin  paddle 
between  the  concrete  and  the  form,  moving  the  handle  to  and 
fro,  up  and  down.  This  movement  forces  the  broken  stone  in 
the  concrete  away  and  brings  a  coating  of  mortar  next  to  the 
form,  which  gives  a  smooth  surface.  Care  taken  in  manipula- 
tion of  concrete  along  the  moulds  will  be  amply  repaid  by  the 
smooth  surface  resulting,  and  the  saving  in  time  and  expense 
otherwise  made  necessary  in  plastering  over  cavities  and 
smoothing  rough  places. 

Concrete  which  is  exposed  to  the  sun  should  be  soaked  with 
water  each  day  for  a  week  or  two.  This  will  allow  the  interior 
of  the  walls  to  dry  uniformly  with  the  exterior,  and  thus 
prevent  scaling  or  cracking. 

Concrete  should  never  be  placed  under  water  if  it  possibly 
can  be  avoided,  because  the  materials  are  in  danger  of  sepa- 
rating. The  danger  of  the  fine  material  separating  from  the 
coarse  was  illustrated  in  a  little  test  made  by  the  engineers 
constructing  the  Holyoke  Dam.  A  small  batch  of  concrete 
was  mixed  in  proportions  one  part  cement  to  two  and  one- 
quarter  parts  sand  to  five  parts  stone,  and  shoveled  into  a  pail 
of  water  with  a  trowel.  The  surface  hardened  satisfactorily, 
and  after  several  months  the  water  was  poured  off  and  the 
material  taken  out.  Instead  of  being  concrete,  three  layers 
were  found.  On  top  was  a  thin  layer  of  practically  neat 
cement,  then  about  2  or  3  inches  of  mixed  sand  and  cement  in 
a  porous  mortar,  then  below  this  a  mixture  of  sand  and  stone 
as  separate  and  clean  as  before  the  concrete  was  mixed. 

This  experiment  and  other  tests  show  that  if  concrete  has 
to  be  placed  under  water  it  must  be  deposited  in  large  masses 
and  never  by  shovelfuls. 

26 


On  small  work  put  the  concrete  in  pails,  place  a  board  over 
the  top  of  the  pail  and  lower  it  carefully  into  the  water  to  the 
bottom.  Turn  the  pail  upside  down,  carefully  remove  the 
board  and  slowly  raise  the  pail,  allowing  the  concrete  to  flow 
out.  Great  care  must  be  used  not  to  disturb  the  water  in 
which  the  concrete  is  being  placed  nor  to  touch  the  green 
concrete.  Concrete  must  never  be  placed  under  water  if  there 
is  any  current,  because  the  cement  will  be  washed  away, 
leaving  only  the  sand  and  stone. 

Another  method  for  depositing  concrete  under  water  is  to 
pass  the  concrete  slowly  through  a  spout  or  tube  which  reaches 
to  within  a  couple  of  inches  of  the  bottom  where  the  concrete 
is  to  be  placed.  The  tube  must  be  kept  full  and  the  concrete 
kept  moving  continuously  and  slowly  through  it.  On  large 
work  specially  designed  buckets  are  used  for  depositing  the 
concrete  under  water,  but  these  are  generally  operated  by  a 
derrick. 

Surface  finish  of  concrete  may  be  for  either  of  two  purposes : 
To  make  the  concrete  more  water-tight,  or  to  improve  the 
appearance.  It  is  advisable  to  leave  the  outside  surface  of  the 
concrete  just  as  it  comes  from  the  forms,  having  used  care  in 
placing  to  see  that  there  are  no  stone  pockets  or  voids ;  or  else 
to  take  off  the  skin  of  cement  so  as  to  expose  the  sand  and 
stone  and  leave  an  even  but  slightly  rough  surface. 

PURE  CEMENT  WASH.  On  exterior  surfaces  a  coat  of 
pure  cement  will  check  with  fine  hair  cracks  because  of  the 
rapid  drying  out  of  the  mortar.  However,  for  the  interior  of 
a  tank  which  will  be  kept  wet  while  in  use,  a  coat  of  neat 
cement  may  serve  to  make  the  concrete  more  water-tight. 
Put  this  on  just  as  soon  as  the  forms  are  removed,  and  take  off 
forms  as  early  as  possible.  In  small  pieces  of  concrete,  like  a 
small  trough,  the  inner  form  may  be  removed  within  two  or 
three  hours,  and  the  wash  applied  immediately.  Leave  the 
outside  forms,  however,  until  the  concrete  is  hard.  Wet  the 
inside  surface  thoroughly  and  apply  the  pure  cement  with  a 
brush  or  a  trowel. 

REMOVING  SURFACE  SKIN  OF  CEMENT  WHILE 
CONCRETE  IS  GREEN.  The  best  method  of  obtaining  a 
good  outside  finish  is  to  rub  off  the  skin  of  cement  which  comes 
to  the  surface  next  to  the  forms  and  thus  expose  the  sand  or 

27 


PLACING 

CONCRETE 

UNDER 

WATER 

(Cont'd.) 


SURFACE 
FINISH 


stone.  There  are  various  ways  of  doing  this.  The  easiest 
way  is  to  remove  the  forms  as  soon  as  the  concrete  is  set, 
which  for  a  wall  may  be  in  24  or  48  hours;  just  as  soon,  in 
fact,  as  the  concrete  will  bear  the  pressure  of  the  thumb.  Wet 
the  surface  thoroughly,  and  rub  it  with  a  brick,  or  with 
a  board  with  a  plasterer's  wooden  float,  or  with  a  carborundum 
block.  By  this  plan  the  surface  can  be  simply  smoothed  of 
roughnesses,  or  the  skin  of  cement  can  be  taken  off  to  leave  a 
sandy  finish,  or  by  still  further  work  the  stones  can  be  exposed. 
The  resulting  finish,  while  rough,  should  be  uniform  and 
pleasing. 

PICKED  SURFACE.  If  the  concrete  has  hardened,  the  skin 
of  cement  can  be  removed  with  a  tool.  A  stone  cutter's  bush 
hammer  can  be  used  for  this,  or  a  tool  can  be  made  with  a 
toothed  edge. 

PLASTERING.  Plastering  on  exterior  surfaces  requires 
great  care  and  skill  to  prevent  cracking  and  peeling.  The 
forms  in  which  the  concrete  is  laid  must  be  wet  instead  of  oiled. 
Roughen  the  surface,  either  when  the  concrete  is  green,  by 
rubbing  off  the  cement,  or  by  picking  the  hardened  surface 
with  an  old  hatchet  or  a  stone  axe.  Wet  thoroughly  and  apply 
as  thin  a  layer  as  possible,  about  1/16  inch  thick  is  best,  of 
mortar,  one  part  "ATLAS"  Portland  Cement  and  one  part 
fine,  but  very  clean,  sand.  For  thick  layers,  pick  and  wet  the 
surface,  then  brush  on  a  thin  coat  of  pure  cement  grout  on  a 
small  part  of  the  surface,  and  before  this  has  begun  to  stiffen 
apply  the  plaster. 

REINFORCED  Reinforced  concrete  is  ordinary  concrete  in  which  iron  or 

f ONf R  FTF 

steel  rods  or  wire  are  imbedded.  Reinforcement  is  required 
when  the  concrete  is  liable  to  be  pulled  or  bent,  as  in  beams, 
floors,  posts,  walls  or  tanks,  because,  while  concrete  is  as 
strong  as  stone  masonry,  neither  of  these  materials  has  nearly 
so  much  strength  in  tension  as  in  compression.  Moreover, 
concrete  alone,  like  any  natural  stone,  is  brittle,  but  by 
imbedding  in  it  steel  rods  or  other  reinforcements,  the  cement 
adheres,  and  the  metal  binds  the  particles  together  so  that  the 
reinforced  concrete  is  better  adapted  to  withstand  jar  and 
impact.  Even  railway  bridges  are  built,  not  only  in  arch  form, 
like  a  stone  arch,  but  in  some  cases  like  a  steel  girder  bridge, 
with  a  flat  reinforced  concrete  floor  supported  by  horizontal 
beams  of  the  same  material. 

28 


Reinforcement  may  be  iron  or  steel.  Steel  is  nearly  always 
used  because  it  is  nowadays  cheaper  than  iron  and  easier  to 
buy.  The  ordinary  iron  rods,  so-called,  as  found  in  the  stores 
are  almost  always  steel. 

Round  rods  or  square  twisted  rods,  or  rods  with  special 
surfaces  designed  to  better  pervent  pulling  out  from  the  con- 
crete, are  used  in  most  of  the  important  work  in  reinforced 
concrete.  For  slabs,  metal  fabrics  like  expanded  metal  or 
woven  wire  is  frequently  used  instead  of  rods.  In  some  of  the 
smaller  structures  described  in  the  pages  which  follow,  the 
reinforcement  is  put  in  to  prevent  cracking,  and,  as  stated  in 
the  text,  almost  any  kind  of  wire  can  often  be  used.  Nearly 
every  farmer  has  fence  wire  which  is  well  adapted  for  reinforc- 
ing watering  troughs  and  for  small  pieces  of  work. 

Concrete,  like  other  materials,  shrinks  when  the  weather 
is  cold,  and  it  also  shrinks  in  setting,  so  that  a  long  wall  is; 
bound  to  have  occasional  cracks  in  it  unless  it  is  very  heavily 
reinforced  or  unless  joints  are  placed  every  30  feet  or  so. 

An  engineer  or  architect  experienced  in  reinforced  concrete 
design  should  be  employed  in  preparing  the  plans  for  houses, 
barns  or  other  large  structures,  but  by  carefully  following  the 
directions  and  specifications  in  this  booklet  small  reinforced 
concrete  construction  may  be  safely  undertaken  by  the 
inexperienced. 

The  table  which  follows  gives  the  thickness  and  reinforce- 
ment of  slabs,  and  the  dimensions  and  reinforcement  of  rein- 
forced concrete  beams  for  a  number  of  conditions  which  are 
liable  to  be  met  with  in  common  practice.  While  the  values 
are  as  low  as  should  be  adopted  without  knowing  the  local 
conditions,  complete  mathematical  calculations  of  dimensions 
should  be  made  for  large  structures,  not  only  from  the  stand- 
point of  safety,  but  also  because  of  the  saving  in  cost  of  mate- 
rial which  can  be  effected  by  fitting  each  member  in  its  proper 
place. 

Rules,  which  are  written  as  footnotes  to  the  table,  give 
very  important  directions. 

An  invariable  rule  in  placing  steel  is  to  insert  it  in  the  face 
where  the  pull  will  come.  Thus  in  a  beam  or  slab  it  must  be 
close  to  the  bottom.  In  a  wall,  to  withstand  earth  pressure,  it 
must  be  in  the  face  nearest  the  earth.  If,  for  example,  a  beam 
were  designed  according  to  the  table,  but  the  steel  placed  in 

29 


REINFORCED 

CONCRETE 

(Cont'd.) 


III 


50 


3     1 


s  = 

II-' 


-g 


LI 


11 


Q 


X  rt' 

Q     l 


a 


\O  LO  t^       \O  LO  t^ 


CO         LO  ON  T-H  O  *-H  CN 

^  ^H  -H  CN  r-l  ^  ^H 


t"»  CO  ON        t^-  CO  O 


^  \0  CO          Tt  \o  CO 


1       .S 

g    -s 

0             0 

.s     >» 

W            .Q 

i     1 

•s    -5 

.a      c 

5      ° 

S    -a       c 

S              § 

s  ^     2 

•3        rt            -0 

s  2     •§».. 

"-•        o             <u        C  M 

113     P       ^    -S.S 

<"       ^           ^       rt»O 

3   8     's^-g.i 
J>  5     8-1  8-1 

1  1   «™ 

1  -    a-o5|i 
1  |    ^!! 

^ 

W         K             13  E  O  0  O 
O)        4)            O  tn"4"1 

•£     -s        fo  _,  aaa 

1  i   tin! 

o 

M 

£ 

I  L  M^Z 

1    |1    Sp.E.E 

hes  fro 

3    g      <    ««•" 

.£ 

10        VO              t^ 

1 

£ 

4) 

os     1  2  14 

tn                     -ii          »H                     O 

W 

e 

J3O               nj       c  ^ 

.  o              a     -1  a) 

£_ 

3     •            oi         rt           ^^ 

%       E     fe      •§» 
&H         rt     JH       *  a 

1 

•SS-^     ?       og 

rii  |  i 

o^jfe  S     S      5rS 
^  t;  0  a     a)      -T3  4-> 

1 

SHIS  11 

* 

rds,  one  rod  in  three, 
3p  of  beam  and  over  si 
aped  with  bent  ends. 
aced  at  right  angles  tc 

lightly  smaller  rods  or 
arallel  to  beams. 
3  metal  mesh  may  be  ; 
ea  of  section  of  metal  is 

rt  «  ^    c.     .     0.   o  b 

Bend,  diagonally  upw 
i  points  in  beam  to 
Stirrups  are  made  U-s 

Slab  reinforcement  is  > 
Fig.  9.) 
Cross  reinforcement  oi 
also  placed  in  slabs 
Wire  fabric  or  expand 
slabs,  provided  the  £ 

1. 

2. 
3. 


the  middle  or  top  of  the  beam  instead  of  in  the  bottom,  it  would 
certainly  break  under  a  very  light  load.  There  must  be  only 
enough  concrete  outside  of  the  steel  to  protect  it  from  rusting 
or  fire.  In  floor  or  roof  slabs  of  small  structures  this  thickness 
should  be  one-half  inch  to  three-quarters  inch  below  the 
bottom  of  the  steel,  and  for  beams  from  one  to  one  and  one- 
half  inches. 

A  typical  beam  with  its  connecting  floor  slabs,  the  concrete 
of  both  of  which  should  be  laid  at  the  same  operation,  is  shown 
in  Fig.  9.  It  will  be  seen  that  the  beam  reinforcement  consists 
of  rods  running  lengthwise  of  the  beam — one-half  or  one-third 
of  these  rods  being  bent  up  about  one-third  way  from  each  end 
and  extending  over  the  supports,  as  shown  in  Fig.  9  and  for 
the  heavier  beams  U-shaped  bars  or  stirrups  are  used  which 
pass  under  the  longitudinal  rods  and  up  on  each  side  of  the 
beam.  The  horizontal  bars  withstand  the  direct  pull  in  the 
bottom  of  the  beam  due  to  bending  when  a  load  is  placed  upon 
it ;  the  U-bars  or  stirrups  and  the  bent-up  bars  prevent  diagonal 
cracks,  which  sometimes  occur  under  loading,  and  the  bars 
passing  over  the  supports  prevent  the  cracking  of  the  beam  on 
top  at  the  ends. 

The  steel  in  the  slab  is  placed  just  above  the  bottom  surface 
at  the  center  of  the  span  and  then  bent  upward  over  the  sup- 
ports as  shown  in  the  drawing. 

Proportions  for  all  reinforced  concrete  must  not  be  leaner 
than  one  part  "ATLAS"  Portland  Cement,  two  parts  clean, 
coarse  sand  and  four  parts  broken  stone  or  clean  screened 
gravel.  Maximum  size  of  broken  stone  or  gravel  should  not 
be  over  one  inch  diameter  in  order  to  pass  between  and  under 
the  steel  rods.  Consistency  of  concrete  should  be  like  heavy 
cream. 

COST  OF  CON-         The  cost  of  concrete  work  varies  considerably  on  account 

^  WORK 

of  the  many  elements  entering  into  the  work.  For  instance, 
the  cost  of  building  the  various  structures  illustrated  in  this 
book  may  be  very  small,  as  the  work  itself  may  be  done  by 
the  owner  or  farmer  at  odd  times  or  with  comparatively  cheap 
help,  while  in  building  with  other  materials,  either  brick  or 
wood,  it  is  necessary  to  employ  carpenters  or  masons.  More- 
over, even  if  the  lumber  for  the  forms  costs  nearly  as  much  as 
the  lumber  for  a  wooden  structure,  as  is  sometimes  the  case,  it 

32 


need  not  be  thrown  away,  but  may  be  used  again  for  other 
purposes.  If  hired  laborers  and  carpenters  do  the  work  it  may 
be  stated  as  a  general  rule  that  concrete  is  always  more  expen- 
sive in  first  cost  than  wood.  On  the  other  hand,  concrete  does 
not  rot,  it  does  not  burn,  and  it  does  not  have  to  be  painted,  so 
that  it  frequently  may  be  cheaper  in  the  long  run.  Besides 
this,  more  unique  and  pleasing  effects  may  be  produced. 

MATERIALS  FOR  ONE  CUBIC  YARD  OF  CONCRETE. 


PROPORTION  BY  PARTS 

Bbls. 

Bbls. 

Bbls.  Gravel 

Cement  in 

Sand    in 

or  Stone  in 

Cement 

Sand 

Stone  or 
Gravel 

1  Cubic 
Yard 

1  Cubic 
Yard 

1  Cubic  - 
Yard 

1 

1* 

3 

2.00 

3.00 

6.00 

1 

2 

4 

1.57 

3.14 

6.28 

1 

2* 

5 

1.29 

3.23 

6.45 

1 

3 

6 

1.10 

3.30 

6.60 

FIRE  RESISTANCE.  Concrete  is  one  of  the  best  fireproof 
materials  known.  It  resists  intense  heat  better  than  iron, 
steel,  ordinary  brick  or  stone,  and  in  the  San  Francisco  and 
Baltimore  fires  it  stood  the  test  better  than  any  other  material. 
It  can  therefore  be  depended  upon  to  resist  any  ordinary  fire. 
Concrete  is  used  extensively  as  a  fire-protective  covering  for 
steel,  for  which  purpose  about  two  inches  is  necessary.  In 
reinforced  concrete  the  iron  or  steel  should  be  imbedded  one 
or  two  inches  for  protection. 

WATER  TIGHTNESS.  By  mixing  wet  and  using  pro- 
portions one  part  "ATLAS"  Portland  Cement  to  one  and  one- 
half  parts  sand  to  three  parts  screened  gravel  and  placing  in 
one  continuous  operation,  so  that  no  surface  is  allowed  to 
harden,  or  else  by  forming  very  good  joints  as  described  on 
page  112,  concrete  is  watertight  under  ordinary  conditions. 
Long  walls  to  resist  water  pressure  must  be  well  reinforced 
to  prevent  cracks  due  to  temperature  contraction,  since  con- 
crete expands  and  contracts  with  temperature  just  like  other 
materials. 

CORROSION  OF  METAL  REINFORCEMENT.  Concrete 
properly  proportioned  and  mixed  wet  absolutely  prevents  any 
metal  imbedded  in  it  from  rusting. 

SEA  WATER.  Concrete  resists  sea  water,  provided  it  is 
properly  proportioned  with  first-class  materials  and  is  carefully 
laid. 


EFFECT  OF 

EXTERNAL 

AGENCIES  ON 

CONCRETE 


33 


1 


GO 
GO 

« 


bfl 


34 


ACIDS.  After  concrete  has  thoroughly  hardened  it  resists 
acids  better  than  almost  any  other  material.  A  substance  like 
manure,  because  of  the  acid  which  it  contains,  has  been  known 
to  slightly  injure  the  surface  of  green  concrete,  but  after  the 
concrete  has  hardened  for  at  least  a  week  it  is  proof  against 
injury. 

OILS.  When  concrete  is  properly  made  and  the  surface  care- 
fully finished  and  is  hardened  before  the  oil  comes  against  the 
concrete,  it  can  be  depended  upon  to  resist  the  action  of  almost 
any  oil. 

ALKALIES.  For  use  in  the  arid  regions  where  there  is 
alkaline  ground  water,  concrete  should  be  especially  rich,  dense 
and  water-tight. 

FREEZING.  Concrete  work  should  be  avoided  so  far  as 
possible  in  freezing  weather,  as  the  frost  will  prevent  the 
bonding  of  different  layers  and  will  cause  a  thin  scale  to  peel 
off  of  the  surface  of  concrete. 

It  is  a  good  rule  to  follow,  therefore,  never  to  lay  concrete 
if  the  temperature  is  below  freezing  or  liable  to  fall  below 
freezing  in  a  day  or  two. 


CONCRETE  FENCE  POSTS  AT  SIOUX  RAPIDS,  IOWA 
35 


POSTS. 

FENCE  POSTS.  The  use  of  concrete  fence  posts  is  becoming  very  general. 
This  is  due  not  only  to  the  scarcity  and  high  price  of  good  straight  wood  posts, 
but  to  the  almost  unlimited  life  of  the  concrete  post,  its  greater  strength  and 
more  pleasing  appearance. 

Concrete  fence  posts  should  be  a  little  larger  than  wood  fence  posts,  and 
may  be  made  either  straight  for  the  whole  length  or  slightly  tapering.  Five 
or  six  inches  square  at  the  bottom  and  four  or  five  inches  square  at  the  top  is  an 
ordinary  size,  or  for  convenience  in  molding  they  may  not  be  made  exactly 
square,  say,  6  inches  by  5  inches  at  the  bottom  and  5  inches  by  4  inches  at 
the  top,  this  size  being  selected  for  the  form  shown  in  Fig.  10. 

As  a  very  slight  heaving  of  a  fence  post  by  frost  is  not  objectionable,  they 


IZCopper  Wire 


Fig.  10.     Design  of  Forms  for  Fence  Posts. 

do  not  need  to  be  placed  in  the  ground  more  than  2^2  feet,  although  if  for  any 
reason  they  should  be  absolutely  rigid  the  lower  end  should  go  below  frost 
line,  which  in  the  Northern  States  is  as  much  as  4  feet  down.  The  length  of 
the  post  is  determined  by  the  height  which  is  desired  above  the  ground. 

Posts  may  be  built  separately,  that  is,  in  a  separate  form  laid  on  the 
ground,  but  the  cheapest  way  is  to  build  forms  for  a  number  of  posts  so  that 
several  can  be  molded  at  the  same  time,  and  then  the  forms  used  for  another 
set  as  soon  as  the  concrete  has  hardened. 

36 


To  mold  a  lot  of  posts  at  one  time  build  the  forms  in  the  following  manner : 
Select  some  place  where  the  posts  can  be  left  in  their  original  position  for 
at  least  ten  days.  Level  off  the  ground  and  place  the  bottom  planks,  which 
should  be  of  i^-inch  or  2-inch  planed  lumber,  side  by  side  upon  2  or  3  cross 
sills,  making  a  solid  floor  upon  which  to  mold  the  posts.  Place  two  i-inch 
by  5-inch  boards  on  edge  parallel  to  each  other  and  the  height  of  the  posts 
apart  and  brace  them  on  the  outside  with  triangular  braces  as  shown  in  the 


CONCRETE  FENCE  POSTS  AT  FAR  ROCKAWAY,  L.  I. 

figure.  To  locate  the  center  of  first  post  stretch  a  line  from  one  side  across  to 
the  other  at  right  angles  to  the  boards  on  edge  as  indicated  by  line  AA.  At 
one  end  of  this  line  AA  measure  3  inches  each  side  of  it  for  the  bottom  of  the 
post  and  at  the  other  end  measure  2  inches  each  side  of  this  line  for  the  top  of 
the  post.  This  will  locate  the  boards  BB  for  the  sides  of  the  posts.  Nail 
these  intermediate  boards  at  the  ends  with  a  nail  or  two  to  the  two  parallel 
boards,  allowing  the  heads  to  project  so  they  can  be  pulled  out  with  a  claw 
hammer. 

Make  the  posts,  as  is  shown  in  the  sketch,  with  every  alternate  post  lying 
the  opposite  way.  By  so  doing  one  intermediate  board  serves  as  a  side  to 
two  posts,  thus  requiring  less  lumber  per  post  than  by  any  other  arrangement 

37 


of  forms.  With  this  method  of  construction  also  the  least  amount  of  ground 
area  is  required  for  molding  the  posts  and  no  bracing  is  necessary  to  support 
the  boards  for  the  sides  of  the  posts.  Triangular  i-inch  bevel  strips  may  be 
placed  on  all  edges,  as  shown  in  the  cross  section,  Fig.  10,  which  will  give  the 
posts  a  neat  and  pleasing  appearance.  These  bevel  strips  can  be  obtained 
readily  from  a  mill,  or  they  may  be  sawed  from  a  i-inch  board  by  ripping  the 
board  lengthwise.  If  desired  the  top  of  the  post  can  be  finished  with  a  taper 
by  simply  inserting  a  triangular  block,  as  shown  at  C  in  Fig.  10.  Never  plaster 
the  top  of  any  post ;  instead,  remove  the  end  form  when  the  concrete  is  green 
and  smooth  the  surface  with  a  trowel  or  float. 

If  straight  instead  of  tapering  posts  are  preferred,  the  same  kind  of  a 
form  as  has  just  been  described  can  be  used  for  molding  them  except  that 
the  intermediate  boards  B  are  placed  at  right  angles  to  the  two  long  parallel 
boards  instead  of  at  angle  to  them,  as  shown,  making  them  5  inches  apart. 
The  forms  are  now  ready  to  fill  and  the  quantities  of  material  for  certain  size 
posts  can  be  taken  from  the  following  table. 

QUANTITY  OF  MATERIAL  FOR  FENCE   POSTS 
All  Posts  Are  4x5  Inches  at  Top;  All  Posts  are  5x6  Inches  at  Bottom. 

One-Half  Small  Single  Load*  of  Sand  Required  per  Barrel  of  Cement ;  One  Small    Single 

Load  *  of  Screened  Gravel  or  Stone  Required  per  Barrel  of  Cement. 

Proportion:  1  Part  "Atlas"  Portland  Cement;  2  Parts  sand; 

4  Parts  Gravel  or  Stone. 


Length  of  Posts, 
Feet 

No.    of    Posts    per    Barrel 
(4  Bags)  of  Cement 

Weight  per  Post, 
Pounds 

5 
6 
7 
8 
9 

20 
17 
14 
12 
.11 

130 
160 
180 
210 
234 

*  Small  single  load  =  1 5  cubic  feet. 

The  posts  should  be  made  with  one  part  "ATLAS"  Portland  Cement, 
two  parts  clean,  coarse  sand  and  four  parts  broken  stone  or  gravel,  about 
i  inch  diameter  particles.  Grease  or  oil  the  form  and  fill  the  bottom  of  the 
form  with  concrete  to  a  depth  of  i  inch,  upon  which  place  immediately  two 
pieces  of  %-inch  round  or  steel  rods  or  No.  6  wire  i  inch  in  from  each  side 
and  running  the  full  length  of  the  post.  Then  quickly  fill  the  form  to  within 
i  inch  of  the  top  with  concrete,  tamping  the  wet  concrete  slightly  to  drive 
out  any  air  bubbles.  Next  place  two  more  rods  or  wires,  each  i  inch  from 
each  side  and  fill  in  the  rest  of  the  concrete,  spading  the  faces  of  the  posts 
next  to  the  form  boards  to  leave  a  smooth  surface,  and  lightly  trowel  the  top 
surface.  The  end  boards  and  the  boards  between  the  posts  must  not  be 
removed  until  the  concrete  is  hard  and  the  posts  should  not  be  handled  or 

38 


moved  for  at  least  ten  days  without  danger  of  cracking  them.  They  should 
be  left  for  three  or  four  weeks  at  least  before  using  and  kept  damp  by 
sprinkling.  The  surfaces  of  the  posts  do  not  need  to  be  finished  off  in  any 
special  way,  for  they  should  be  smooth  enough  without. 

For  fastening  fence  wire  to  the  posts,  the  following  method  is  suggested: 
Take  a  piece  of  No.  12  copper  wire  12  inches  long,  bend  it  in  two  and  twist 
the  halves  together,  leaving  the  ends  free  for  about  2  inches;  these  should  be 
made  beforehand.  While  the  concrete  is  being  placed  in  the  forms  set  two 
or  three  of  these  copper  wires  in  the  concrete  the  proper  distance  for  stringing 


VIEW  OF  DELLWOOD  PARK  FENCE,  JOLIET,  ILL. 

wires  so  that  they  will  be  imbedded  in  the  post  about  4  inches  and  leave  the 
two  free  ends  to  project  from  the  post  about  2  inches.  See  cross  section  of 
post  in  Fig.  10. 

Another  very  good  method  is  to  get  a  number  of  ^-inch  or  i-inch  round 
rods  or  wood  dowells  6  or  8  inches  long  and  place  them  vertically  in  the  form 
the  proper  distance  apart  for  stringing  wires.  To  hold  them  in  place  nail  a 
strip  of  wood  across  the  top  of  the  form  beside  the  rod  and  drive  a  nail  into 
this  strip  and  bend  the  nail  around  the  rod  so  as  to  hold  it  up  against  the 
strip.  The  rods  should  be  well  greased  and  left  in  the  concrete  about  i  day, 
when  they  can  be  removed.  If  they  are  not  well  greased  it  will  be  almost 
impossible  to  remove  them  without  injuring  the  concrete.  Through  the  holes 

39 


CONCRETE  FENCE    AT  GEDNEY  FARMS,  WHITE  PLAINS,  N.  Y. 


CONCRETE  GATE  POSTS  AT  COLUMBIA,    MO. 
40 


the  fence  wire  can  be  strung,  or  a  short  piece  of  wire  can  be  run  through  and 
the  ends  twisted  around  the  running  fence  wire. 

There  are  several  other  methods  of  providing  the  same  means  of  attaching 
the  fence  wire  to  the  posts.  For  instance,  insert  in  place  of  the  copper  wire 
described  above  a  galvanized  screw  eye  and  run  the  fence  wire  through  it  or 
attach  it  to  the  screw  eye  by  means  of  wires. 

CORNER  POSTS.  Corner  posts  should  be  made  about  10  inches  square  the 
full  length  of  the  posts  and  9  feet  long.  On  account  of  the  weight  of  such  a 
large  post  it  is  easier  to  mold  the  posts  in  place,  as  they  will  weigh  about  940 
pounds,  but  if  desired  they  can  be  made  in  the  same  manner  as  the  other 
fence  posts  just  described.  Reinforce  corner  posts  with  a  3^-inch  rod  in  each 
corner  of  the  post  instead  of  the  No.  6  wire  used  for  the  smaller  ones.  Set  a 
corner  post  at  least  3^  feet  in  the  ground.  If  special  finish  is  necessary,  refer 
to  method  of  treating  horse  blocks,  page  43. 


QUANTITY  OF  MATERIAL  FOR  CORNER  POSTS 
One-Half  Small  Single  Load*  of  Sand  Required  Per  Barrel  of  Cement;  One  Small  Single 

Load*  of  Screened  Gravel  or  Stone  Required  Per  Barrel  of  Cement. 
Proportions:  1  Part  "Atlas"  Portland  Cement  to  2  Parts  Sand  to  4  Parts  Gravel. 


SIZE   OF  POSTS 

No.  of  Posts  per 
Barrel   (4  Bags) 
Cement 

Weight  per  Post, 
Pounds 

Length,  Feet 

Top,  Inches 

Bottom,  Inches 

6 

12 

12 

2M 

900 

7 

12 

12 

2y2 

1,050 

8 

12 

12 

234 

1,200 

9 

12 

12 

2 

1,350 

9 

10 

10 

3 

940 

9 

6 

6 

8 

337 

7 

24 

24 

K2 

4,200 

Small  single  load  =15  cubic  feet. 


COST  OF  FENCE  POSTS.  Seven-foot  fence  posts  constructed  as  described 
on  page  36,  without  hiring  outside  help  so  that  the  cost  of  labor  need  not  be 
considered,  can  be  made  for  about  2oc.  to  soc.  each.  They  will  cost  from  ice. 
to  2oc.  apiece  more  if  the  cost  of  labor  is  considered. 

HITCHING  POSTS.  Hitching  posts  can  be  built  and  reinforced  in  the  same 
manner  as  finished  fence  posts.  Make  a  post  about  6  feet  long  so  that  it  will 
set  about  2^4  feet  in  the  ground.  Make  forms  and  handle  the  concrete  same 
as  described  above  for  fence  posts.  Cast  a  long  %-inch  diameter  iron  staple, 
holding  an  iron  ring,  in  the  top  of  the  post  by  passing  it  through  a  slot  in  the 
head  of  the  form  before  the  concrete  is  poured,  just  as  the  staple  is  placed  in 
the  clothes  post  described  on  page  following. 

41 


A  neat  and  inexpensive  round  hitching  post 
may  be  designated  as  the  "stove-pipe"  hitching 
post.  Dig  a  hole  18  inches  deep  and  10  inches 
in  diameter  in  the  ground  and  fill  with  one  part 
"ATLAS"  Portland  Cement,  two  parts  of  clean, 
coarse  sand  and  four  parts  of  screened  gravel 
or  broken  stone.  Place  on  this  base  of  con- 
crete, before  it  has  set,  a  section  of  y-inch  stove 
pipe.  For  reinforcement  place  a  i-inch  gas  pipe 
in  the  center  of  the  stove  pipe  and  push  it  into 
the  soft  base  of  concrete.  Insert  in  top  of  post  a 
round  hitching  post  ring.  Leave  the  stove  pipe 
in  place  and  paint  it  if  desired,  which  makes  a 
very  neat  and  attractive  post.  When  the  stove 
pipe  rusts  off,  the  concrete  post  still  remains  as 
attractive  as  ever. 


CONCRETE  CLOTHES  POSTS  AT  WESTWOOD,  N.  J. 

42 


STOVE-PIPE  HITCHING  POST 
AT  COLUMBIA.  MO. 

CLOTHES      POSTS. 

Clothes  posts  may  be 
made  in  the  same  general 
way  as  the  finished  fence 
posts,  except  that  they 
should  be  6  inches  square, 
9  feet  long,  and  rein- 
forced with  ^-inch  rods 
in  each  corner  instead  of 
No.  6  wire.  Imbed  an 
iron  staple  J/£  inch  in 
diameter  in  the  top  of 
the  post  for  a  clotheo 
line.  This  can  be  done 
by  cutting  a  hole  in  the 
head  of  the  form  large 
enough  to  pass  the  eye 
of  the  staple  through, 
then  placing  the  staple 
before  the  concrete  is 
poured  and  hold  it  in 
place  by  a  wad  of  paper 
to  plug  the  hole.  An- 
other plan  is  to  form  a 


hole  near  the  top  of  the  post  by  placing  a  greased  dowel  in  the  form  before 
pouring  the  concrete. 

HORSE   BLOCKS. 

Horse  blocks  can  be  built  solid  in  place. 

Make  a  form  or  box,  without  a  bottom,  36  inches  long,  18  inches  wide  and 
12  inches  deep,  inside  dimensions.  Grease  this  form  and  fill  with  concrete, 
one  part  "ATLAS"  Portland  Cement,  two  and  one-half  parts  clean,  coarse 
sand  and  five  parts  screened  gravel  or  broken  stone. 

It  is  best  not  to  plaster  the  top  surface  or  sides  of  the  block,  for  if  it  is 
plastered  it  is  apt  to  crack  or  peel  off.  The  top  surface  should  be  smoothed  off 
with  a  trowel  when  the  concrete  is  first  laid,  then  in  a  few  hours,  as  soon  as  it 
has  begun  to  stiffen,  scrape  off  any  light  colored  scum  with  a  wire  brush  or 


HORSE  BLOCK,  HITCHING  POST  AND  SIDEWALK  AT  WESTWOOD,  N.  J. 

horse  curry  comb,  and  trowel  the  surface  again,  preferably  with  a  wood  float, 
but  using  no  fresh  mortar.  The  form  should  be  removed  the  next  day,  or  as 
soon  as  the  concrete  is  hard  enough  not  to  show  thumb  marks,  and  while  the 
concrete  is  green  rub  down  the  sides  with  a  wood  float  or  brick.  Keep  damp 
by  sprinkling  for  a  week.  If  the  surface  thus  left  is  not  good  enough,  it  may 
be  necessary  to  plaster  it,  even  though  at  the  risk  of  checking  and  cracking. 
To  do  this  pick  the  surface  with  a  stone  axe,  wet  thoroughly  and  trowel  on  a 
coat  of  mortar  one  part  "ATLAS"  Portland  Cement  to  one  part  clean,  fine 
sand,  making  the  layer  not  over  1-16  inch  thick. 

43 


The  weight  of  a  horse  block  of  the  above  dimensions  is  about  675  pounds 
and  about  two  bags  of  cement  are  needed. 

WATERING   TROUGHS. 

One  of  the  most  useful  and  essential  devices  about  a  farm  is  the  small 
watering  trough,  and  when  made  of  concrete  it  is  not  only  of  pleasing  appear- 
ance, but  is  practically  indestructible.  Moreover,  if  an  inlet  pipe  with  float 
valve  connection  has  been  provided  it  needs  absolutely  no  attention. 

Watering  troughs,  like  many  other  concrete  structures,  may  be  made 
without  steel  reinforcement,  but  if  so  constructed  the  walls  must  be  half  again 
as  thick  as  when  reinforced,  and  even  then  are  more  apt  to  crack.  The  size 
and  capacity  of  the  trough  varies  with  the  purpose  for  which  it  is  used,  but 


WATERING  TANK,  BOODY,  ILL. 

for  troughs  up  to  about  10  feet  long  by  2  feet  wide  by  2  feet  deep  the  thickness 
of  the  reinforced  walls  should  be  about  5  inches. 

It  is  essential  that  a  watering  trough  be  water-tight.  The  conditions  for 
obtaining  a  trough  which  will  not  leak  are  (i)  a  richer  mix  of  concrete  than 
is  required  for  ordinary  work;  (2)  enough  water  in  mixing  to  give  a  sloppy 
concrete,  and  (3)  the  placing  of  all  the  concrete  at  one  operation.  It  is 
extremely  difficult  to  make  any  structure  water-tight  unless  all  three  of  the 
above  conditions  are  complied  with. 

44 


FIELD  TROUGH  AT  GEDNEY  FARMS,  WHITE  PLAINS,  N.  Y. 


WATERING  TROUGH  AT  BERRY  HILL,  L.  I. 
45 


The  best  mix  of  concrete  to  use  varies  with  the  sand  and  gravel  employed, 
but  generally  speaking  one  part  of  "ATLAS"  Portland  Cement  to  one  and  one- 
half  parts  of  clean,  coarse  sand  to  three  parts  of  screened  gravel  or  broken 
stone  are  advised,  or  if  gravel  from  the  natural  bank  is  used  without  screening, 
one  part  of  "ATLAS"  Portland  Cement  to  three  parts  of  natural  bank  run 
gravel.  If  sand  alone  is  available  use  one  part  "ATLAS"  Portland  Cement  to 
two  parts  sand. 

The  amount  of  excavation  necessary  for  the  foundation  of  a  trough  depends 
upon  the  size.  For  a  small  trough  level  off  the  earth  and  tamp  the  ground 
well  before  placing  any  concrete,  but  for  a  trough  of  large  capacity  a  solid 


WATERING  TROUGH,  DECATUR,  ILL. 

foundation  should  be  used.  To  construct  a  solid  and  reliable  foundation, 
excavate  about  12  inches  and  fill  in  6  inches  with  either  cinders  or  gravel  from 
which  the  sand  has  been  screened,  tamp  this  well  and  fill  in  6  inches  of 
concrete,  using  only  half  the  proportion  of  cement  to  sand  and  stone  that  is 
used  for  the  trough  itself. 

Next  place  the  outer  forms  in  position,  brace  and  oil  them  well  and  mix 
the  concrete  according  to  the  directions  given  on  page  24. 

Place  a  2^-inch  layer  of  concrete  in  the  form,  and  immediately  after 

46 


placing  and  before  the  concrete  has  set,  place  a  sheet  of  woven  fence  wire  or 
some  other  wire  fabric  over  the  concrete,  bending  it  up  so  that  it  will  come 
to  within  one  inch  of  the  top  of  the  forms  at  the  sides  and  ends.  Place  2% 
inches  more  of  the  concrete  in  the  bottom  and  ram  lightly  to  bring  the  mortar 
to  the  surface  and  smooth  it  off  evenly.  Have  the  inner  form  all  ready  and 
as  soon  as  the  base  is  laid  and  before  it  has  begun  to  stiffen  set  it,  taking  care 
to  keep  it  at  equal  distances  from  the  sides,  and  then  immediately  fill  in  the 
concrete  between  the  outer  and  inner  forms  to  the  required  height.  The 
time  at  which  to  remove  the  form  depends  upon  several  conditions,  such  as 
the  wetness  of  the  concrete,  the  weather  and  the  temperature,  but  generally 


FIELD  WATERING  TROUGH,  KNOXVILLE,  IOWA 

such  forms  can  be  removed  within  two  days.  After  removing  the  forms,  wet 
the  concrete  thoroughly  and  paint  the  inside  surface  with  pure  "ATLAS" 
Portland  Cement  mixed  as  thick  as  cream.  Protect  the  trough  from  the  sun 
until  it  is  filled  with  water  keeping  it  wet  for  about  a  week.  Do  not  fill  with 
water  until  a  week  after  laying  the  concrete. 

The  outside  surface  can  be  finished  off  very  satisfactory  if  done  as  soon  as 
the  forms  are  removed  by  wetting  the  surface  thoroughly  with  a  whitewash 
brush,  using  plenty  of  water,  and  rubbing  it  down  with  a  wood  float  or  board 

47 


or  a  brick.  This  will  remove  the  marks  of  the  form  boards  and  make  a  very 
pleasing  appearance.  (See  directions  for  Finishing  Concrete  Surfaces,  page 
27).  A  long  trough  is  difficult  to  build  because  of  the  great  amount  of  rein- 
forcement required  to  prevent  shrinkage  cracks. 

Where  the  trough  is  to  be  connected  with  an  inlet  and  outlet  pipe,  it  is 
best  to  place  the  necessary  pipes  and  connections  in  the  forms  before  laying 
the  concrete.  This  will  save  a  great  deal  of  labor  and  trouble,  but  where 
these  connections  cannot  be  made  before  placing  the  concrete,  the  holes  for 
them  may  be  provided  in  the  concrete  by  inserting  greased  wooden  plugs  in 
the  forms  in  place  of  the  pipes.  These  plugs  can  be  easily  withdrawn  as  soon 
as  the  concrete  has  set. 


Fig.  ii.     Design  of  Forms  for  Rectangular  Trough. 

The  design  of  forms  for  a  rectangular  trough,  shown  above,  is  economical 
in  that  the  lumber  for  the  outside  forms  does  not  need  to  be  cut  unless 
desired,  and  can  therefore  be  used  for  any  other  purpose,  being  practically 
as  good  as  new. 

18 


WATER  TROUGH  AT  MONROE,  N.  J. 


OLD  BOILER  TANK  WATERING  TROUGH  AT  COLUMBIA,  MO. 
49 


Were  it  not  for  the  more  complicated  form  work,  the  circular  shaped  tank 
would  be  built  oftener  because  of  the  attractive  effects  which  can  be  produced. 

A  simple  and  attractive  circular  form  for  a  small  watering  trough  is  shown 
in  Fig.  12.  It  is  made  as  follows: 


ft  (Overflow  Pipe 

nt  Wagon 
Wheel  Tire. 


Fig.  12.     Design  of  Forms  for  Circular  Trough. 

Take  an  old  wagon  or  buggy  tire,  lay  it  on  the  ground,  and  mark  a  line  on 
the  inside  of  the  tire.  Excavate  inside  of  tire  6  inches  deep  and  place  endwise 
three  i  by  2-inch  stakes  about  3  feet  long  on  the  inside  of  the  tire.  Raise 
the  tire  2  feet  above  the  ground  to  make  the  total  inside  depth  of  the  trough 
2  feet,  and  drive  a  nail  in  each  of  the  three  stakes  under  the  tire  to  support  it 
at  this  height.  Fill  in  the  circle  between  these  three  stakes  with  slats  or 
flooring  boards  set  on  end  and  place  a  nail  in  each  under  the  tire  to  hold  them 
at  the  top.  To  hold  them  at  the  bottom  tamp  a  little  sand  at  the  foot  of  the 
stakes.  Mix  one  part  "ATLAS"  Portland  Cement  to  one  and  one-half  parts 
of  clean,  coarse  sand  to  three  parts  of  screened  gravel  or  broken  stone  and 
lay  about  4  inches  of  concrete.  Place  the  reinforcement  as  described  for 
rectangular  troughs,  running  it  up  on  the  sides  so  that  it  is  about  2  inches 
from  the  outside  surface.  After  placing  the  reinforcement  the  rest  of  the 
operations  are  the  same  as  for  a  rectangular  trough.  The  inside  form  may 
be  made  by  sawing  a  barrel  in  two,  nailing  each  of  the  barrel  staves  to  the 
head  of  the  barrel,  and  removing  all  but  the  top  hoop.  The  construction  of 
the  inside  barrel  form  is  clearly  shown  in  Fig.  12.  Oil  the  forms  well  before 
placing  the  concrete. 

The  materials  required  for  a  circular  trough  like  this  are  3*^2  bags  of 
"ATLAS"  Portland  Cement  and  i  single  load  of  sand  and  gravel.  Two 
men  can  make  a  trough  in  about  one-half  day  each,  and  the  cost  is  approxi- 
mately $4.00  complete. 

So 


A  single  load  of  sand  or  gravel  is  considered  as  20  cubic  feet,  or  3^  of  a 
cubic  yard,  and  a  double  load  as  40  cubic  feet,  or  nearly  i^  cubic  yards. 

A  method  of  constructing  a  circular  trough  where  a  cut  off  section  of  an 
old  boiler  was  used,  not  only  for  the  exterior  form,  but  also  as  the  outside 
finish,  is  shown  in  the  photograph  above.  This  style  of  trough,  although 
rather  attractive,  is  more  expensive  than  the  one  just  described  on  account  of 
the  cut  off  boiler  section,  which  in  this  case  was  about  $10.00. 


DIPPING  TANK  AT  CHILLICOTHE,  OHIO 

A   desirable   hog   trough   can   be   made   by   building   a 


HOG  TROUGHS. 

bottomless  box  6  feet  long  and  12  inches  broad  by  12  inches  deep.  From  a 
2-inch  plank  saw  out  two  triangles  having  a  base  of  12  inches  and  a  height  of 
8  inches.  Place  these  5  feet  6  inches  apart  and  nail  a  plank  i  inch  thick  on 
each  side  of  the  triangle.  Place  the  inverted  V-shaped  trough  thus  made  inside 


the  bottomless  box  and  put  small  triangular  strips  around  the  edges  to  make 
a  square  edge.  (See  Fig.  No.  13.)  Grease  the  form  thoroughly  and  fill  the 
space  left  with  concrete  mixture,  one  part  "ATLAS"  Portland  Cement  and 
three  parts  clean  sand  or  sandy  gravel,  tamp  lightly,  and  smooth  off  to  top  of 
box.  Let  stand  until  dry.  Remove  the  inner  forms  within  3  or  4  hours,  and 
paint  the  inside  with  pure  "ATLAS"  Portland  Cement,  mixed  as  thick 
as  cream. 


Fig.  13.     Forms  for  Hog  Troughs. 

Should  a  trough  with  a  round  bottom  be  desired,  an  inner  form  can  be  made 
by  sawing  a  log  the  right  length,  stripping  it  of  bark,  and  splitting  in  half. 
Put  this  in  the  bottomless  box  described  above,  flat  side  down  (Fig.  No.  25), 
grease  well  and  proceed  as  with  triangular  trough. 

SLOP  TANKS. 

Every  farm  should  have  one  or  more  slop  tanks,  in  order  to  heat  the 
slop  and  prevent  it  from  freezing,  so  that  the  cattle  can  be  fed  no  matter  how 
cold  it  may  be. 

Slop  tanks  of  concrete  have  proved  satisfactory.  A  concrete  slop  tank 
should  be  made  of  one  part  "ATLAS"  Portland  Cement  to  two  and  one-half 
parts  clean,  coarse  sand  to  five  parts  of  screened  gravel  or  stone.  The  size 
shown  in  Fig.  12  will  require  12  bags  of  cement,  1^2  single  loads  of  sand  (20 
cubic  feet  per  single  load)  and  3  single  loads  of  screened  gravel,  or  better 
still,  clean  cinders. 

A  36-inch  iron  kettle,  having  a  capacity  of  75  gallons,  costs  about  $7.00  in 
the  city  market,  to  which  the  freight  must  be  added.  The  forms  are  very 
simple,  and  can  be  easily  made  by  a  man  in  a  day.  The  inner  form  need  not 
be  removed,  but  can  be  burnt  out  the  first  time  a  fire  is  built  in  it.  The  tank 
must  be  well  reinforced  in  order  to  keep  it  from  cracking,  due  to  the  difference 
in  temperature  to  which  the  tank  is  subject.  The  firing  is  done  from  the  door 
left  in  the  front  and  the  stack  takes  care  of  the  draft.  Do  not  build  a  fire 
in  the  tank  until  the  concrete  has  set  for  at  least  two  weeks. 


stovepipe 


'W 

Ground  J/rre 


Long/fud/naf     \Se  c  ffon 

Fig.  14.    Concrete  Slop  Tank. 


53 


FERTILIZING  TANKS. 

Fertilizing  tanks  should  be  made  about  the  shape  of  and  a  little  larger 
than  a  barrel.  If  carefully  made  they  will  withstand  the  rough  usage  to 
which  they  are  subjected  by  being  pulled  from  place  to  place  on  drags,  and 
are  unaffected  by  the  fertilizing  fluids.  Make  the  tank  about  2^  inches  thick 
and  well  reinforced.  As  soon  as  inside  form  is  removed  wet  and  brush  with  a 
layer  of  pure  "ATLAS"  Portland  Cement  of  the  consistency  of  thin  cream 
to  make  it  water-tight.  Keep  the  inside  wet  until  it  is  to  be  used. 


SLOP  TANK  AT  MORTON,  ILL. 

RAIN    LEADERS. 

Rain  leaders  or  gutters  are  best  constructed  of  concrete  because  they  can 
be  made  for  a  very  small  cost,  need  no  forms,  are  indestructible,  and  very 
attractive. 

Excavate  a  trench  4  inches  deep  by  9  inches  wide  in  the  sand  or  dirt  from 
the  end  of  the  rain  conductor  to  the  required  distance  from  the  building.  Make 
a  small  batch  of  concrete,  in  proportions  one  part  "ATLAS"  Portland  Cement 
to  four  parts  unscreened  sand  and  gravel,  and  fill  the  trench,  hollowing  out 
the  surface  and  troweling  a  little  to  form  the  trough.  The  water  may  be 
carried  under  the  surface  if  desired  by  digging  a  deeper  trench,  placing  it  in  a 

54 


FERTILIZING  TANK,  GREENHOUSE  AND  RUSTIC  SEAT  AT  WESTWOOD,  N.  J. 


RAIN  LEADERS,  DUMONT,  N.  J. 
55 


length  of  tin  or  sheet-iron  pipe  and  surrounding  this  with  concrete.    When  the 
pipe  rusts  out,  the  concrete  tube  will  still  remain. 

RETAINING  WALLS. 

Concrete  retaining  walls  in  most  localities  cost  much  less  than  rubble 
masonry.  The  design  of  the  retaining  walls  shown  in  Fig.  15  is  what  is  known 
as  the  gravity  section,  which  means  that  the  earth  pressure  is  resisted  by  the 
weight  of  the  wall.  The  following  table  gives  the  necessary  dimensions  and 


RETAINING  WALL  AT  DUMONT,  N.  J. 

the  amount  of  materials  per  foot  of  length  of  wall.  The  amount  of  material  is 
figured,  assuming  that  the  concrete  is  made  of  one  part  "ATLAS"  Portland 
Cement,  two  and  one-half  parts  of  clean,  coarse  sand,  and  five  parts  of 
screened  gravel  or  stone.  The  foundation,  as  shown,  is  taken  4  feet  below 
the  ground  level.  In  the  Southern  States,  3  feet,  or  even  2  feet,  will  be 
sufficient  to  get  below  the  frost  line. 

The  exposed  side  or  face  of  the  retaining  wall  can  be  finished  off  in  the 
same  manner  as  described  on  page  27.  The  top  surface  must  not  be  plastered 
or  it  will  crack  and  is  apt  to  peel  off.  The  surface  should  be  smoothed  off  with 
a  trowel  when  the  concrete  is  first  laid,  then  as  soon  as  it  has  begun  to  stiffen 
scrape  off  any  light-colored  scum  with  a  wire  brush  or  old  curry  comb,  wet 
slightly,  and  trowel  it,  preferably  with  a  wood  float,  but  using  no  fresh  mortar. 

56 


bH 


.-»V.<»V^;  ".'jj^^SS^S^ 

isif 
iii 

:•!»:*. -:;*V.-,r- 

J££3v££? 

&.*•"•>  :VP:.SV  • 
:?:«7-:>v6.;:;o,; 

3»$l 

£*&$$:) 

•a..  ••  o  ;• ;  'o v  -.  •<:>•  • , 
•^•Y'V.\Y:  •*.:•.'.«? 


.•e;'<3 


,.;.-    ,-p  ..«,.1'0i>\l4««i 

;-V^:«^vi?v?5-;^ 

«V:A»iV::^-*i'!-'?:V 

;-.V;:V:?V^::^o:: 

•..•l-j.TJi--*-.-^/.^-':  4 
a.  •* 


Fig.  15.     Design  for  Retaining  Wall. 

DIMENSIONS  OF  RETAINING  WALLS  AND  QUANTITY  OF  MATERIALS 

FOR  DIFFERENT  HEIGHTS  OF  WALL. 

Proportions:  1  Part  "Atlas"  Portland  Cement  to  2}£  Parts  Sand  to  5  Parts  Gravel  or  Stone. 

(See  Figure  15.) 


Height  of 
Wall 

Total 

Thickness 

Thickness 
at 

Thickness 

AMOUNT    OF    MATERIALS    PER 
ONE  FT.  LENGTH  OF  WALL 

Above 
Ground 

Height 
of  Wall 

at 
Base 

Ground 
Level 

at 
Top 

Cement 

Sand 

Gravel  or 

B 

A 

Stone 

Feet 

Feet 

Ft.      In. 

Ft.     In. 

Inches 

Bags 

Cu.  Ft. 

Cu.  Ft. 

2 

6 

2          2 

1        6 

10 

1  ^ 

43^ 

9 

3 

7 

2          5 

i     iy> 

JO 

2^/2 

sy2 

11 

4 

8 

2          9 

i    11 

i2 

3 

7 

14 

5 

9 

3          1 

2        1 

12 

3  /2 

9 

19 

6 

10 

3          6 

2        43^ 

15 

4% 

23 

7 

11 

3        10 

2        8 

18 

6 

14 

28 

8 

12 

4          2 

2      10 

18 

7 

I6M 

33 

Note: — A  large  single  load  of  sand  or  gravel  is  about  20  cubic  feet. 
A  large  double  load  of  sand  or  gravel  is  about  40  cubic  feet. 

57 


DAMS. 

If  a  dam  is  to  be  built  more  than  4  or  5  feet  above  the  bed  of  the  stream, 
an  engineer  should  be  called  upon  to  design  it  and  look  after  the  construction. 

For  an  ice  pond  or  a  pond  for  watering  stock  a  concrete  dam  may  be  built 
across  a  brook  without  difficulty. 

If  possible,  dig  a  temporary  trench  so  as  to  carry  the  water  around  the  dam 
while  it  is  being  built.  If  this  cannot  be  done,  run  the  water  through  a  wooden 
trough  in  the  middle  of  the  dam,  and  after  the  wall,  each  side  of  it,  is  finished, 


DAM  AT  ARLINGTON,  VA. 

carry  the  forms  across  the  opening,  and  make  these  tight  enough  so  that  the 
water  is  quiet  between  them ;  then  place  the  concrete  as  described  on  page  26. 
Dig  a  trench  across  the  stream  slightly  wider  than  the  width  of  the  base  of 
the  dam,  carrying  it  down  about  18  inches  or  2  feet  below  the  bed  of  the  brook, 
or  if  the  ground  is  soft,  deep  enough  to  reach  good,  hard  bottom.  In  case  the 
earth  is  firm  enough  for  a  foundation,  but  is  porous  either  under  the  dam  or 
each  side  of  it,  sheet  piling  consisting  of  2-inch  tongued-and-grooved  plank 
can  be  pointed  and  driven  with  a  heavy  wooden  mallet  so  as  to  prevent  the 
water  flowing  under  or  around  the  dam.  Build  the  forms  so  as  to  make  the 

58 


wall  of  the  dimensions  shown  in  the  table.     Wet  them  thoroughly,  then  mix 
and  place  the  concrete  as  described  on  page  24. 

Use  proportions  one  part  "ATLAS"  Portland  Cement  to  two  parts  clean, 
coarse  sand  to  four  parts  screened  gravel  or  broken  stone. 

Take  special  care  to  make  the  concrete  water-tight  by  using  a  wet  mix. 
If  possible,  lay  the  entire  dam  on  one  day,  not  allowing  one  layer  to  set  before 

the  next  one  is  placed.  If  it  is  necessary  to  lay 
the  concrete  on  two  different  days,  scrape  off 
the  top  surface  of  the  old  concrete  in  the  morn- 
ing, thoroughly  soak  it  with  water,  and  spread 
on  a  layer  about  %  inch  thick  of  pure  cement 
of  the  consistency  of  thick  cream,  then  place 
the  fresh  concrete  before  this  cement  has  begun 
to  stiffen. 

If  the  forms  on  the  lower  side  of  the  dam 
are  well  braced,  the  forms  on  the  upstream  side 
may  be  removed  in  three  or  four  days,  and  the 
pond  allowed  to  fill.    The  forms  on  the  down- 
stream face  should  be  left  in  place 
well  braced  for  two  or  three  weeks. 

^•:7'1/:*^:.^V^'*'^^^8^P      No  finish  need  be  given  to  the  sur- 
?.•;•&£  ?£••  v  :v.  >*:  *m  face. 


Fig.  1 6.     Design  for  Dam. 

DIMENSIONS  FOR  SMALL  DAMS  AND  QUANTITY  OF  MATERIALS  FOR 

DIFFERENT  HEIGHTS  OF  DAMS. 

Proportions:  1  Part  "Atlas"  Portland  Cement  to  2  Parts  Sand  to  4  Parts  Gravel  or  Stone. 

(See  Fig.  16.) 


Height 
Above 
Bed  of 
Stream 

Depth 
Below 
Bed  of 
Stream* 

Thickness 
at  Base 

Thickness 
at  Top 

AMOUNT  OF  MATERIALS  PER  FOOT 
OF  LENGTH  OF  DAM 

Cement 

Sand 

Gravel  or 
Stone 

Feet 
H 

Feet 
G 

Feet 
B 

Feet 
T 

Bags 

Cu.  Ft. 

Cu.  Ft. 

1 
2 
3 
4 
5 
6 

^A 
\y> 

W 

2 

2 

1 
1 
2 
2 
2H 

1 
1 
1M 
1H 
1H 

\y> 

y> 

1*4 

23/4 

3^ 
4H 

H 

IK- 

4 
5 
6% 
8% 

1H 

8 
10 
13H 

\r& 

*  Make  deeper  if  necessary  to  get  a  good  foundation. 


Note: — A  large  single  load  of  sand  or  gravel  is  about  20  cubic  feet. 
A  largw  double  load  of  sand  or  gravel  is 


is  about  40  cubic  feet. 


59 


WALLS. 

Concrete  walls  are  everywhere  being  built  in  preference  to  stone,  on 
account  of  the  lower  cost  and  thinner  walls  which  are  usually  required.  Unless 
stone  can  be  laid  at  practically  no  expense,  the  concrete  is  cheaper. 

Every  wall  should  have  a  footing,  that  is,  a  base  wider  than  the  wall  it 
supports,  and  must  be  carried  down  below  the  frost  line.  The  depth  of  such 
footings,  therefore,  must  be  varied  according  to  the  section  of  country  in  which 
the  work  is  being  done.  In  general,  they  should  be  about  4  feet  below  the 
ground  level  in  the  Northern  and  Middle  States,  and  about  3  feet  in  the 
Southern  States,  while  in  very  mild  climates  2  feet  will  be  sufficient.  The 
footing  should  be  not  less  than  4  to  6  inches  thick  and  should  extend  about  the 
same  distance  each  side  of  the  wall. 


HOUSE  FOUNDATION  AT  SUMMIT,  N.  J. 

Care  must  be  taken  to  see  that  the  foundation  is  not  placed  on  a  soft  and 
yielding  soil.  Where  the  soil  is  unsuitable,  either  excavate  until  rock  or  a 
better  material  is  found,  fill  in  up  to  frost  line  with  gravel  and  tamp  it  well 
while  placing.  When  there  is  any  danger  of  this  filling  of  gravel  forming  a 
pocket  in  which  the  water  will  accumulate,  dig  a  ditch  away  from  the  wall  so 
that  the  water  will  run  off. 

CELLAR  AND  BASEMENT  WALLS.  Cellar  or  basement  walls  must 
withstand  the  earth  pressure  that  comes  upon  them.  This  pressure  varies 
with  the  depth  of  the  cellar  or  basement,  and  hence  the  thickness  of  the  walls 

60 


CONCRETE  HOUSE  AT  DECATUR,  ILL. 


CONCRETE  HOUSE  NEAR  MORTON,  ILL. 
6l 


should  vary  with  the  depth  as  shown  in  the  following  table: 

THICKNESSES    OF   WALLS   AND    QUANTITIES   OF   MATERIALS   FOR    DIFFERENT 

HEIGHTS  OF  BASEMENTS. 

Proportions:  1  Part  "Atlas  "  Portland  Cement  to  2A  Parts  of  Sand  to  5  Parts  of 

Gravel  or  Stone. 


Depth  of 

Cement  per 

Sand  per 

Gravel  or 

Height 

Foundation 

Thickness 

Thickness 

10  Ft.  of 

10  Ft.  of 

Stone  per 

of 

Below 

of  Wall    ' 

of  Wall 

Length  of 

Length  of 

10  Ft.  of 

Basement 

Ground 

at  Bottom 

at  Top 

Wall 

Wall 

Length  of 

Level 

Wall 

Feet 

Feet 

Inches 

Inches 

Bags 

Cubic  Feet 

Cubic  Feet 

6 

4 

6 

6 

6 

14^ 

29 

8 

6 

10 

8 

12 

29 

58 

10 

8 

15 

10 

25^ 

60 

120 

The  thicknesses  are  less  than  for  a  retaining  wall  out  of  doors  because  the 
weight  of  the  building  and  the  floor  timbers  strengthen  it.  The  back  of  the 
wall  may  batter  or  slope  to  save  concrete.  If  vertical  use  bottom  thickness  for 
the  full  height.  The  earth  must  not  be  filled  in  against  the  back  of  the  wall 
until  three  or  four  weeks  after  placing  the  concrete  unless  the  forms  and 
bracing  are  left  in  place  in  front. 


I  in.  Board's 

-/n.  C/ecrte 


Fig.  17.     Cellar  Wall  Forms. 
62 


Where  there  is  no  earth  pressure  against  the  wall  let  the  forms  remain 
not  less  than  24  hours,  or  until  the  concrete  will  withstand  the  pressure  of 
the  thumb. 

Fig.  17  illustrates  a  simple  design  for  cellar  or  foundation  walls:  (a)  of 
the  figure  represents  view  of  an  ordinary  form,  2-inch  by  4-inch  braces  being 
attached  to  the  studs  as  braces;  the  form  sides  do  not  extend  to  the  bottom 
so  as  to  allow  the  concrete  to  flow  out  and  form  a  spread  footing;  (b)  repre- 
sents a  wall  for  which  the  bank  of  earth  serves  as  one  side  of  the  form.  This 
condition  may  occur  when  the  soil  is  of  a  clayey  nature,  which  does  not  cave 
in,  or  where  the  new  wall  is  being  built  against  an  old  one. 


CONCRETE  BARN  AT  TAMPICO,  ILL. 

Cellar  or  basement  walls  should  be  laid  with  one  part  "ATLAS"  Portland 
Cement  to  two  and  one-half  parts  coarse  sand  and  five  parts  of  broken  stone 
or  screened  gravel. 

As  concrete  is  the  best  material  for  cellar  walls  or  footings  of  any  kind,  it 
is  often  used  for  this  purpose  even  where  the  rest  of  the  building  is  of  wood 
or  any  other  material.  The  building  foundation  should  be  brought  up  to  the 
required  height  above  the  ground  level.  To  attach  the  wood  superstructure  to 
the  concrete  foundation  place  on  the  concrete,  imbedding  it  in  mortar,  the 
wood  sill,  which  is  made  with  the  ends  halved  and  bolted  together.  In  the 
West,  where  the  winds  are  very  strong,  this  sill  must  be  bolted  to  the  concrete ; 
this  is  done  by  placing  occasional  bolts  in  the  concrete  when  laying  it,  letting 

63 


the  nut  end  protrude  above  the  foundation  to  bolt  through  the  sill.  Holes  can 
then  be  bored  in  the  sill  to  fit  over  the  protruding  bolts  and  the  nuts  placed, 
thus  firmly  securing  it. 


Fig.  1 8.     Wall  Forms. 

WALLS  ABOVE  CELLAR  OR  BASEMENT.  Concrete  walls  above  the 
cellar  may  be  built  either  as  a  single  solid  wall  or  as  two  walls  with  an  air 
space  between  them.  Such  an  air  space  renders  the  building  less  subject  to 
changes  of  temperature  and  more  completely  moisture  proof,  but  it  is  more 
expensive. 

A  solid  concrete  wall  6  inches  thick  is  at  least  equivalent  to  12  inches 
of  brick.    Walls  6  inches  in  thickness  should  be  reinforced  with  vertical  rods 

64 


*/4  inch  in  diameter  placed  18  inches  apart  and  with  horizontal  rods  %  inch  in 
diameter  placed  12  inches  apart.  Additional  rods  must  be  placed  at  corners 
and  diagonally  across  the  corners  of  all  openings.  Walls  of  small  buildings, 
such  as  hen  houses,  may  be  made  4  inches  thick  with  the  same  reinforcement 
described.  Where  hollow  wall  construction  is  used,  make  each  of  the  walls 
4  inches  thick  and  about  9  inches  apart,  and  tie  together  with  galvanized-iron 
strips,  or  place  piers  of  concrete  4  feet  apart  to  connect  the  two  together. 
Where  such  piers  are  used  they  are  built  at  the  same  time  as  the  two  walls, 
making  practically  one  wall  with  air  chambers  at  regular  intervals.  A  very 
simple  method  to  construct  a  hollow  wall  is  by  using  2-inch  planed  plank,  as 
shown  in  Fig.  31  (p.  102). 


Fig.  19.     Hollow  Wall  Forms.* 


Fig.  1 8  shows  a  design  of  wall  forms  for  building  a  solid  wall  of  any  height. 
The  form  sections  are  each  made  2  feet  high  and  the  length  depends  upon  the 
length  of  boards  at  hand.  A  2-foot  section  made  of  i-inch  boards  10  feet  long 
weighs  55  pounds,  which  can  therefore  be  handled  easily  by  one  man.  The 
cleats  are  made  to  lap  over  the  top  of  the  form  i^  to  2  inches,  in  order  to 
catch  the  next  section  placed  on  top  of  the  one  just  filled  with  concrete.  No- 
tice, also,  that  the  cleat  at  one  end  projects  beyond  the  form  bracing  so  as  to 
catch  the  next  section  and  hold  it  in  place.  Use  bolts  for  holding  the  forms 
together,  as  they  are  better  than  wires,  which  cut  into  the  cleats  and  spring  the 
forms  apart.  The  bolt  holes  left  in  the  wall,  as  shown  in  Fig.  15,  are  a 
means  of  constructing  a  very  efficient  and  cheap  scaffolding.  All  bolts  should 

*See  Footnote,  p.  18. 

65 


CONCRETE  POSTS  FOR  SUPPORTING  TROLLEY  FOR  LITTER  CARRIER  AT  NEWBURGH,  N.  Y. 

be  well  greased  so  that  they  can  be  readily  removed.  After  completing  the 
wall  the  bolt  holes  can  be  filled  with  mortar  mixed  in  the  same  proportion  as 
the  concrete  so  that  the  color  will  be  the  same  as  the  wall. 

Sometimes  a  building  is  built  with  a  wood  superstructure  on  top  of 
concrete  walls  which  are  only  from  four  to  eight  feet  above  the  ground.  In 
this  case  the  wood  superstructure  can  be  attached  to  the  concrete  walls  in  the 
same  manner  as  described  on  page  63  for  connecting  a  wood  building  to  a 
concrete  foundation. 


06 


COLUMNS. 

Excavate  below  frost  and  build  forms  2  feet  square  to  within  6  inches  of 
surface  of  ground.  Fill  with  concrete,  one  part  "ATLAS"  Portland  Cement, 
two  and  one-half  parts  clean,  coarse  sand  and  five  parts  broken  stone  or 
screened  gravel,  not  over  one  inch  in  size,  and  tamp  or  puddle  carefully.  From 
the  center  of  this  foundation  build  a  hollow  form  one  foot  square  and  to  desired 
height,  and  fill  with  concrete  of  same  mixture.  Before  the  form  is  filled — in 
fact,  before  setting  it — place  four  steel  bars  94  mcn  m  diameter  ver- 
tically so  that  they  are  about  2  inches  inside  the  corners,  and  around  them, 


Fig.  20.     Column  Form. 


at  intervals  of  one  foot,  wind  loops  of  ^g-inch  or  ^4-inch  wire,  tying  these  to 
the  steel  rods  with  fine  wire.  Make  the  concrete  soft  and  mushy,  so  that  it 
will  just  flow,  and,  as  it  is  poured  into  the  top  of  the  mold,  work  a  long  paddle, 
made  like  the  oar  of  a  rowboat,  against  the  forms  to  force  the  stones  away 
from  the  surface  and  drive  out  bubbles  of  air  which  tend  to  adhere  to  the 
boards  and  form  pockets  of  stone. 

A  column  10  inches  square,  the  smallest  size  it  is  usually  desirable  to  build 
unless  it  is  quite  short,  will  safely  support  15  tons,  or  30,000  pounds. 

67 


INTERIOR  VIEW  OF  MANURE  PIT  AT  GEDNEY  FARMS,  WHITE  PLAINS,  N.  Y. 


DETAILS  OF  PIERS  AND  FLOOR  BEAMS  UNDER  HORSE  BARN  AT  GEDNEY  FARMS,  WHITE  PLAINS,  N.  Y. 

68 


STEPS   AND   STAIRS. 

Steps  and  stairs  are  of  two  kinds :  those  made  in  one  piece,  monolithic,  and 
those  cast  in  separate  moulds  and  put  into  place.  There  are  numerous  ways 
of  arriving  at  the  same  end,  and  each  man  in  charge  of  such  work  must  use 
his  ingenuity  in  the  use  of  the  materials  at  hand,  and  adopt  the  method  best 
suited  to  his  requirements.  Specifications  are  given  for  four  ways  of  making 
steps  and  stairs,  all  of  which  have  proved  successful. 


FLYING  STAIRS,  DAIRY  HOUSE  AT  GEDNEY  FARMS,  WHITE  PLAINS,  N.  Y. 

The  rises  on  all  steps  and  stairs  should  not  be  less  than  6  inches  nor 
more  than  8  inches,  while  the  tread  should  be  from  9  inches  to  12  inches, 
except  where  it  is  intended  that  more  than  one  step  should  be  taken  on  the 
tread,  in  which  case  30  inches  should  be  the  minimum  width. 

Foundations  for  all  steps  out  of  doors  should  extend  below  frost  line  or 
have  a  porous  base  with  a  drain  situated  at  the  lowest  point  to  allow  the  water 
to  run  off.  Steps  should  be  wider  than  the  walk  or  opening  from  which  they 

69 


SIDEWALK  AND  STEPS  AT  WEST  HAVEN,  CONN. 

lead,  to  avoid  looking  cramped,  and,  in  order  to  secure  an  artistic  effect,  should 
have  some  sort  of  projection,  or  moulding,  at  the  upper  edge.  A  slight  slope 
to  allow  the  water  to  run  off  is  also  desirable. 

Let  us  first  consider  steps  to  areas  or  terraced  grounds.    Excavate  the  earth 
on  the  slope  to  the  desired  depth  (see  Foundations  for  Sidewalks)  and  put  in 


Mortar  Finish 


/^^SSSSlg^Sg^^ 


Fig.  21.     Concrete  Steps. 
70 


porous  foundation  with  a  drain  at  the  lower  end  to  dispose  of  any  water  that 
may  accumulate. 

Take  two  planks  the  length  of  the  flight  of  steps  on  the  slope,  and  wide 
enough  to  house  each  step,  and  mark  upon  them  the  location  of  the  riser  for 
each  step.  Place  these  planks  edgewise  on  each  side  on  the  slope,  and  brace 


CELLAR  STEPS  AND  ICE  BOX  AT  WESTWOOD,  N.  J. 

well  on  the  outside.  Place  the  necessary  reinforcement,  as  given  in  the  table, 
the  full  length  of  the  steps  on  the  slope.  Now  set  planks  marked  (b.)  Fig.  21, 
across  these  housings  to  form  the  rise  of  each  step  on  the  lines  previously 
marked,  placing  them  so  that  there  will  be  a  space  below  them  for  a  continuous 
slab  of  concrete.  The  thickness  of  the  slab  is  given  in  the  table  under  column 
marked  "A."  These  planks  should  be  arranged  with  a  groove  at  the  top,  as 
shown,  to  form  the  projection  or  moulding  at  the  top  of  each  step.  They 


should  be  fastened  to  the  housing  planks  with  cleats  in  such  a  way  that  they 
can  be  removed  without  disturbing  them.  Inside  of  each  of  these  riser  forms 
place  a  loose  piece  of  board,  well  greased,  as  described  for  facing  curbing  on 
page  79,  so  as  to  provide  a  space  which  can  later  be  rilled  with  mortar.  Now 
pour  into  the  forms  thus  made  concrete  in  proportions  one  part  "ATLAS" 
Portland  Cement,  two  parts  clean,  coarse  sand,  and  four  parts  broken  stone  or 
screened  gravel,  rilling  each  step  to  within  i  inch  of  the  top  of  the  riser.  As 
soon  as  this  concrete  has  stiffened,  but  before  it  has  set,  carefully  draw  out 


PORCH  STEPS  AT  GREENFORT,  L.  I.,  N.  Y. 

the  loose  facing  board  and  fill  the  spaces  with  mortar  one  part  "ATLAS" 
Portland  Cement  to  one  and  one-half  parts  clean,  coarse  sand,  and  also  cover 
over  the  top  of  the  step  to  the  depth  of  i  inch  with  the  same  mortar,  so  that 
it  will  come  flush  with  the  top  of  the  riser  plank.  Float  the  surface  lightly 
with  a  wooden  float,  and  as  soon  as  it  has  stiffened  hard  enough  to  work, 
trowel  it  thoroughly.  Early  next  day  remove  the  riser  form,  the  bottom  of 
which,  as  shown  in  the  figure,  is  beveled  and  comes  only  to  the  top  of  the 
mortar  surface,  and  trowel  the  face  of  each  riser.  A  skilled  plasterer  should 
be  employed  for  this  work,  as  the  surface  is  likely  to  crack  if  not  handled  in  a 
workmanlike  manner. 

Porch  steps,  and  other  short  flights,  can  be  built  as  follows:     Build  two 
8-inch  walls  to  a  depth  below  frost,  the  upper  surface  conforming  to  the  desired 

72 


pitch  of  the  steps,  but  3  inches  below  the  points  where  the  inner  edges  of  the 
treads  meet  the  risers.    Carry  the  outside  form,  however,  on  the  same  slope  to 


>                   * 
k-               ^ 

Gbncrefe 
•^cf/b.rods  ^ 

fei^^lM 

f?  Concrete  Waff 
J<o'  roofing 

Waffs  -fobebLf/ff-befoyv  frost: 


Fig.  23. 
Fig.  22.     Form  for  a  Single  Step. 

Fig.  23.     Single  Steps  in  Place. 

the  line  of  the  top  of  the  risers.  Between  the  walls  build  a  sloping  platform 
out  of  i -inch  boards  supported  by  2  x  4-inch  stuff,  well  braced  and  conforming 
to  the  slope  of  the  walls.  Upon  this  sloping  platform  place  ^4-inch  steel  bars 
12  inches  apart  running  from  top  to  bottom.  Also,  cross  ways  place  one 
3/8-inch  bar  just  at  the  foot  of  each  rise,  and  fasten  these  to  the  ^-inch  bars  by 
soft  wire.  Next  mark  for  the  location  of  the  risers  the  side  forms  which  project 
above  the  8-inch  walls,  place  cross  plank  on  each  to  form  these  risers,  and 
proceed  in  the  same  manner  as  has  been  described  for  area  steps.  Forms 
should  not  be  removed  from  under  the  steps  for  28  days.  Should  the  steps  be 
more  than  6  feet  wide,  a  wall  similar  to  the  two  side  walls  may  be  built  in  the 
center. 

Sometimes  it  is  easier  to  build  a  wall  at  the  top  and  bottom  of  the  steps 
instead  of  at  the  sides,  and  run  the  principal  rods  lengthwise  of  the  flight,  so 
that  it  is  supported  at  top  and  bottom.  In  this  case  the  supporting  slab,  whose 
thickness  must  be  considered  as  the  thinnest  place  in  the  steps,  is  designated 
in  Fig.  21  by  "A."  The  span,  that  is,  the  "distance  apart  of  the  beams,"  in  the 
table  is  taken  as  the  length  of  the  horizontal  projection  of  the  stairs.  The 
thickness  of  the  slab  and  the  diameter  and  spacing  of  the  rods  are  given  in  the 
table  following. 

73 


DIMENSIONS  OF  STAIRS. 
(See  Fig.  21,  Page  70.) 


Distance 
Between 
Floors 
Feet 

Rise 
Inches 

Tread 
Inches 

A 
Inches 

Size 
of  Rods* 
Inches 

Spacing* 
Inches 

No.  of 
Rods 
in  Top 
Beam 

Size  of 
Rods 
in  Top 
Beam 
Inches 

No.  of 

Steps 

10 

iy> 

10 

7« 

or  y8 

4 

1 

H 

16 

9 

71.4- 

10 

6M 

or  ^| 

7^2 

1 

H 

15 

8 

7>2- 

10 

6 

or  % 

8^ 

1 

V8 

13 

7 

7 

10 

5* 

y* 

or  ^s 

534 
9 

1 

H 

12 

6 

7M 

10 

4^ 

or  i/o 

4 

7 

1 

5/8 

10 

5 

7Ji 

10 

334 

or  ^ 

JM 

1 

^ 

8 

4 

7 

10 

3M 

H 

or  Yz 

6 
11 

1 

M 

7 

3 

7M 

10 

2^ 

H 

9 

1 

M 

5 

*  Select  either  size  and  spacing  preferred. 

Steps  cast  separate  from  supporting  walls  should  be  made  in  advance  and 
allowed  to  season.  The  sectional  drawing  illustrates  this  form  of  step.  To 
build  a  single  step,  make  form  shown  in  Fig.  22,  14  inches  x  7  inches  inside 
measurement  and  i  inch  for  projection,  and  fill  as  shown  to  within  i  inch  of 
top  with  concrete,  one  part  "ATLAS"  Portland  Cement,  three  parts  clean, 
coarse  sand,  and  six  parts  broken  stone;  tamp  hard.  As  soon  as  this  has 
stiffened,  but  before  it  has  set,  remove  the  board  "a"  next  to  the  face  of  the 
concrete,  which  should  not  be  fastened  to  the  form,  but  simply  set  in  and  well 
greased.  This  will  leave  a  space  on  the  side  and  top  of  step,  also  a  small  mould 
for  the  projection  at  top  of  step.  Fill  this  with  wet  mortar,  one  part  "ATLAS" 
Portland  Cement  and  one  and  one-half  parts  clean,  coarse  sand,  and  let  set. 
The  side  forms  may  then  be  removed  and  used  again.  The  two  side  walls  for 
these  steps  may  be  8  inches  wide,  spread  at  the  base  by  allowing  the  concrete 
to  flow  out  under  the  forms.  The  top  is  stepped  off  to  conform  to  the  bottom 
and  back  of  steps  (Fig.  23.)  Place  the  steps  on  the  walls  thus  made,  after 
covering  all  joints  with  cement  mortar,  so  that  they  overlap  one  another  2 
inches.  Reinforce  all  steps  and  stairs  cast  separately  by  iron  bars  placed 
about  i  inch  above  the  bottom  of  the  slab. 


74 


SIDEWALKS. 

Before  laying  the  concrete  a  foundation  of  porous  material,  such  as  cinders 
or  screened  gravel,  must  be  placed  and  as  much  care  should  be  taken  in  laying 
this  as  the  walk  itself.  Foundations  should  generally  be  6  inches  to  12  inches 
deep,  depending  upon  the  climate  and  character  of  the  soil.  In  sections  where 
there  is  a  porous  soil  and  a  mild  climate,  foundations  are  sometimes  omitted 
entirely.  If  the  soil  is  clayey,  blind  drains  of  coarse  gravel  or  tile  pipe  should 
be  laid  at  the  lowest  points  in  the  excavation,  to  carry  off  any  water  that  might 
accumulate  in  the  porous  material  of  the  foundation.  Walks  are  frequently 
ruined  by  water  freezing  in  the  foundations  and  heaving  them  out  of  position. 

Excavate  to  the  sub-grade  previously  determined  upon,  3  inches  wider  on 
each  side  than  the  proposed  walk,  and  fill  with  broken  stone,  gravel  or  cinders 
to  within  4  inches  of  the  proposed  finished  surface,  wetting  well  and  tamping 
in  layers,  so  that  when  complete  it  will  be  even  and  firm,  but  porous.  Place 
2-inch  x  4-inch  scantlings  (preferably  dressed  on  inside  and  edge  and  perfectly 
straight)  on  top  of  the  cinder  foundation,  the  proper  distance  apart  to  form 
the  inner  and  outer  edges  of  the  walk.  The  outside  or  curb  strips  must  be  i 
inch  to  2  inches  lower  than  the  inner  edge  of  the  walk.  This  will  give  a  slight 
incline  to  the  finished  surface  and  allow  the  water  to  run  off.  A  good  rule  to 
follow  is  to  allow  3/g-inch  slope  to  every  foot  of  width  of  walk.  For  wide  walks 
lay  off  the  space  between  the  scantlings  into  equal  sections  not  larger  than 
6  feet  square,  put  2-inch  x  4-inch  scantlings  crosswise  and  in  the  center,  as 
shown  in  Fig.  24 — this  will  make  every  alternate  space,  shown  in  figure  by 
diagonal  line,  the  size  desired.  Fill  these  spaces  with  concrete  to  a  depth  of  3 
inches  (this  depth  should  be  4  inches  where  there  is  more  than  ordinary  traffic, 
or  where  the  blocks  are  6  feet  square) — one  part  "ATLAS"  Portland  Cement, 
two  parts  clean,  coarse  sand,  and  four  to  five  parts  broken  stone  or  screened 
gravel — then  tamp  until  water  begins  to  show  on  top.  On  the  same  day,  as 
soon  as  the  concrete  has  set,  remove  crosswise  and  center  scantlings,  place  a 
sheet  of  tar  paper  on  the  edges  to  separate  them  from  all  other  squares  and  fill 
in  the  spaces  thus  left  with  3-inch  concrete  as  before.  Mark  the  scantling  to 
show  where  the  joints  come. 

The  finishing  coat  should  be  i  inch  thick,  of  one  part  "ATLAS"  Portland 
Cement  and  one  and  one-half  parts  clean,  coarse  sand,  or  crushed  stone  screen- 
ings. This  coat  should  be  spread  on  before  the  concrete  has  taken  its  set,  and 
smoothed  off  with  a  screed  or  straight  edge  run  over  the  2x4  scantlings,  the 
object  being  to  thoroughly  bond  the  finishing  coat  to  the  concrete  base.  If  the 
bond  between  the  finishing  coat  and  the  concrete  is  imperfect,  the  walk  gives 
a  hollow  sound  under  the  feet,  and  is  liable  to  crack  after  having  been  down 

75 


,1/TJ 


Cfl 

i 
o 


r 

F.4' 

\    1L 

\ 
\ 

\M 

3 

L 

\ 

'& 

•  52 

\ 

^? 

\ 

2" 

* 

§1 

i 
\ 

bi) 

X 

^b 

\ 
\ 

fe 

[ 

]2>   If 

iT*  x  ^ 

yfc    <f) 

<l 

.«QVJ^ 

c^-s 

^^ 

'".*• 

11 

?;^;;.:! 

«     -  ^ 

\  ^r  '  *^  *  • 

§.5.0 

8  C^ 

»  "C  ^  '  **  f  '   • 

C 

]     \| 

S¥S 

if 

%v^3 

ite 

v       t   * 

'         11    | 
3/cfe  Walks                  ^  §    'O 

one  or  two  years.  Smooth  with  a  wooden  float,  and  groove  exactly  over  the 
joints  between  the  concrete  (Fig.  24),  so  as  to  bevel  the  edges  of  all  blocks. 
Do  not  trowel  the  finishing  coat  too  much,  nor  until  it  has  begun  to  stiffen,  as 
this  tends  to  separate  the  cement  from  the  sand,  producing  hair  cracks,  and 
giving  a  poor  wearing  surface.  Keep  the  finished  walks  protected  from  dust, 
dirt,  currents  of  air  and  the  hot  sun  during  the  process  of  setting,  and  further 

MATERIALS   FOR   100  SQ.   FT.  OF  CONCRETE. 


BAGS  OF  CEMENT  TO  100  SQ.  FT.  OF  CONCRETE 
SURFACE 

BAGS  OF  CEMENT  TO  100  SQ.  FT.  OF  MORTAR 
SURFACE 

Thickness 
Inches 

/    Proportions 

Thickness 
Inches 

i        Proportions 

1:11/^:3 

1:2:4 

1:3:6 

1:  1 

1  :  1  l/2     \      1:2 

3 
4 
5 
6 
8 
10 
12 

8l/o 
11 
14  U 
16M 
22  H 
28% 

34  3/r 

6^ 
8% 
11 

13  M 

18 
213-4 
'61% 

4^ 
6 

^A 

9^ 

12 

15>2 
18K> 

U 

H 
1 

1M 
W 

ik 

3i-i;: 
5 
7 

8M 
10 
12 
14 

2% 
4 

SM 

6^ 
8 

9M 
11 

2M 
3H 
4^ 

sk 

6M 
7% 
9 

SURFACES    LAID    WITH    ONE   BARREL   OF   CEMENT. 


No.  OF  SQ.   FT.  OF  CONCRETE   (BASE)    LAID 
WITH  4  BAGS  (1  BBL.)  OF  CEMENT 


Thickness 
Inches 

Proportions 

Thickness 
Inches 

Proportions 

1:1^:3 

47 
36 
27 
24 
17 
14 
12 

1:2:4 

60 
46 
36 
30 
22 
19 
15 

1:3:6 

1:1 

1:1^ 

1  .2 

3 
4 
5 
6 
8 
10 
12 

83 
66 
52 
41 
33 
26 
21 

Vi 
H 

Ui 
1^ 
1M 

2 

114 
80 

57 
48 
40 
33 
29 

146 

100 
73 
60 
50 
43 
36 

178 
114 
89 
70 
59 
52 
44 

No.  OF  SQ.  FT.  OF  MORTAR  SURFACE  LAID 
WITH  4  BAGS  (1  BBL.)  OF  CEMENT 


NOTE. — Four  bags  of  cement  equal  1  barrel. 

For  proportions  1 :1  %  :3  use  for  every  33  bags  of  cement  1  large  double  load  of  sand  and  2  of  gravel. 
For  proportions  1 :2 :4  use  for  every  23  bags  of  cement  1  large  double  load  of  sand  and  2  of  gravel. 
For  proportions  1 :3 :6  use  for  every  1  5  bags  of  cement  1  large  double  load  of  sand  and  2  of  gravel. 
One  large  double  load  contains  40  cubic  feet  or  1  %  cubic  yards. 


protect  from  the  sun  and  traffic  for  three  or  four  days,  and  keep  moist  by 
sprinkling.  The  covering  may  be  whatever  is  most  convenient — sand,  straw, 
sawdust,  grass,  or  boards. 

Most  walks  are  made  the  width  of  a  single  block,  and  should  be  constructed 
as  shown  in  Fig.  24.  In  a  walk  the  width  of  a  single  block,  make  every 
alternate  block  and  then  go  back  and  fill  in  the  blocks  between. 

77 


CONCRETE  BLOCK  BARN  AT  HARPERSVILLE,  N.  Y. 


COW  BARN  AT  U.  S.  SOLDIERS'  HOME,  WASHINGTON,  D.  C. 
78 


CURB  AND  GUTTER. 

The  foundation  for  curbs  and  gutters,  like  sidewalks,  should  be  governed 
by  the  soil  and  climate. 

Concrete  curbing  should  be  built  in  advance  of  the  walk  in  sectional  pieces 
6  feet  to  8  feet  long,  and  separated  from  each  other  and  from  the  walk  by  tar 
paper  or  a  cut  joint,  in  the  same  manner  as  the  walk  is  divided  into  blocks. 

Curbs  should  be  4  inches  to  7  inches  wide  at  the  top  and  5  inches  to  8 
inches  at  the  bottom,  with  a  face  6  inches  to  7  inches  above  the  gutter.  The 
curb  should  stand  on  a  concrete  base  5  inches  to  8  inches  thick,  which  in 
turn  should  have  a  sub-base  of  porous  material  at  least  12  inches  thick.  The 


Vq 


S-f-re&f- 


•fjj 


^finishing  Goaf 


Concrete 


Concrete 


^r^^^C/ncfers  I 


Curb 


form 


Fig.  25.     Concrete  Curb  and  Gutters. 

gutter  should  be  16  inches  to  20  inches  broad,  and  6  inches  to  9  inches  thick, 
and  should  also  have  a  porous  foundation  at  least  12  inches  thick. 

Keeping  the  above  dimensions  in  mind,  excavate  a  trench  the  combined 
width  of  the  gutter  and  curb  and  put  in  the  sub-base  of  porous  material.  On 
top  of  this  place  forms  and  fill  with  a  layer  of  concrete,  one  part  "ATLAS" 
Portland  Cement,  three  parts  clean,  coarse  sand  and  six  parts  broken  stone, 
thick  enough  to  fill  the  forms  to  about  3  inches  below  the  street  level.  As 
soon  as  the  concrete  is  sufficiently  set  to  withstand  pressure,  place  forms  for 
the  curb,  and,  after  carefully  cleaning  the  concrete  between  the  forms  and 

79 


thoroughly  wetting,  fill  with  concrete,  one  part  "ATLAS"  Portland  Cement, 
two  and  one-half  parts  clean,  coarse  sand  and  five  parts  broken  stone.  When 
the  curb  has  sufficiently  set  to  withstand  its  own  weight  without  bulging, 
remove  the  3/4-inch  board  shown  in  Fig.  25,  and  with  the  aid  of  a  trowel  fill 
in  the  space  between  the  concrete  and  the  form  with  cement  mortar,  one  part 
"ATLAS"  Portland  Cement  and  one  part  clean,  coarse  sand.  The  finishing 
coat  at  the  top  of  the  curb  should  be  put  on  at  the  same  time.  Trowel  thor- 
oughly and  smooth  with  a  wooden  float,  removing  face  form  the  following  day. 
Sprinkle  often  and  protect  from  sun. 

In  making  curbs  alone,  specifications  given  below  and  illustrated  in  sec- 
tional drawing  should  be  followed. 

Excavate  32  inches  below  the  level  of  the  curb  and  fill  with  cinders,  broken 
stone,  gravel  or  broken  brick  to  depth  of  12  inches.  Build  a  foundation  8 
inches  deep  by  12  inches  broad,  one  part  "ATLAS"  Portland  Cement,  three 
parts  clean,  coarse  sand  and  six  parts  broken  stone,  and  from  the  top  of  this 
and  nearly  flush  with  the  rear,  build  a  concrete  wall  nJ4  inches  high,  7^4 
inches  broad  at  the  base  and  6^4  inches  at  the  top,  the  i-inch  slope  to  be  on  the 
face.  Forms  should  be  built  as  in  Fig.  25. 

Remove  the  forms  as  soon  as  the  concrete  will  withstand  its  own  weight 
without  bulging,  and  proceed  as  per  directions  given  on  this  page  (Fig.  25). 
Keep  moist  for  several  days  and  protect  from  the  sun.  The  above  measure- 
ments may  be  varied  to  suit  local  conditions. 


RUBBLE  CONCRETE  BARN  AT  WESTWOOD,  N.  J. 
80 


BARNS. 

Each  year  dairymen  are  realizing  more  and  more  the  necessity  of  improv- 
ing and  changing  their  methods  in  order  to  produce  a  milk  which  contains 
less  bacteria  than  that  of  their  neighbor  or  competitor.  A  number  of  factors 
enter  into  the  accomplishment  of  this  result. 

It  is  stated  by  experienced  dairymen  that  the  material  of  which  the  barn  is 
made  is  of  the  most  vital  importance,  for  this  may  be  the  breeding  place  of 
germs.  With  the  use  of  concrete  this  question  is  solved,  because  a  building  so 
constructed  offers  no  chance  for  the  germs  to  nest.  If  one  goes  a  step  further 
and  constructs  the  floors,  troughs,  stalls  and  other  fixtures  all  of  concrete, 
perfect  hygienic  conditions  are  realized,  and  the  road  is  clear  to  securing  a 
germ-proof  milk. 


Fig.  26.     Section  of  Cow  Barn  Floor. 


FEED   TROUGHS. 

Many  designs  of  feeding  troughs  have  been  used,  but  most  of  them  are 
objectionable  from  a  hygienic  standpoint.  A  concrete  feeding  trough,  shown 
in  section  in  Fig.  26,  is  similar  to  the  trough  developed  after  considerable 
study  by  the  well-known  dairy  expert,  Mr.  S.  L.  Stewart,  and  used  by  him  at 
Somers  Center,  N.  Y.,  and  elsewhere. 

This  design  has  a  high  front  end,  slanting  instead  of  straight,  in  order  to 
avoid  scratching  and  bumping  it  with  the  carts  and  to  keep  them  out  of  the 
drain  in  front.  Use  the  same  design  of  forms  for  the  slanting  front  as  that 
shown  in  the  figure,  except  place  the  bottom  of  the  form  8  inches  in  from 
the  vertical.  Make  the  inside  of  the  trough  at  the  center  either  on  a  level 
with  the  top  of  the  finished  floor  or  about  2  inches  above  it,  and  give  it  a  slope 
of  3  inches  in  50  feet  in  order  to  readily  drain  the  water  at  the  lower  end. 

81 


INTERIOR  VIEW  OF  BARN  AT  GLEN  COVE,  L.  I. 


FEED-MIXING  TROUGH  AT  U.  S.  SOLDIERS'  HOME,  WASHINGTON,  D.  C. 

82 


Some  of  the  features  which  this  trough  incorporates  are : 

(1)  The  front  of  the  trough  is  low  so  that  it  does  not  catch  tne  breath  of 
the  cow,  and  still  is  high  enough  to  prevent  the  material  from  being  spilled  out 
unnecessarily. 

(2)  Only  a  minimum  amount  of  water  need  be  run  into  the  trough,  and 
still  it  will  be  deep  enough  to  allow  the  cattle  to  drink  freely. 

(3)  The  trough  is  of  such  a  width  that  the  least  amount  of  material  is  apt 
to  be  thrown  out  of  the  trough  by  the  cattle. 


INTERIOR  VIEW  OF  BARN  AT  BROOKSIDE  FARM,  NEWBURGH.N.  Y. 

The  following  costs  of  concrete  troughs  are  figured  from  actual  data  taken 
by  a  contractor  on  a  job  in  New  York.  These  values  checked  almost  exactly 
with  those  given  by  another  contractor  in  a  different  section  of  the  country. 
The  comparison  was  made  possible,  of  course,  by  assuming  the  unit  cost  of 
material  and  labor  the  same  for  both  jobs,  thus  placing  them  on  the  same  basis. 
A  trough  such  as  is  shown  in  Fig.  26  contains  about  3^/2  cubic  feet  of  con- 
crete per  running  foot  of  trough.  It  should  be  made  with  one  part  "ATLAS" 
Portland  Cement  to  two  and  one-half  parts  clean,  coarse  sand,  to  five  parts  of 
stone,  and  finished  with  a  one-inch  coat  of  one  part  "ATLAS"  Portland 
Cement  to  one  and  one-half  parts  of  sand.  The  amount  of  material  needed 

83 


CONCRETE  HORSE  BARN  AT  GEDNEY  FARMS,  WHITE  PLAIKS,  N.  Y. 


COW  BARN  AT  BABYLON,  L.  I. 
84 


per  10  linear  or  running  feet  of  trough,  including  the  top  finish,  is  ten  bags  of 
cement,  one  single  load  of  sand  (reckoning  20  cubic  feet  per  load),  and  three 
quarters  of  a  single  load  of  gravel.  Thus  the  cost  per  running  foot  of  trough 
for  material  only  is  about  70  cents,  considering  cement  at  $2.00  per  barrel, 
sand  at  75  cents  per  cubic  yard,  and  gravel  at  $1.25  per  cubic  yard.  The  cost 
of  labor  is  about  44  cents  per  running  foot,  considering  labor  at  $2.00  per  day. 
This  makes  the  total  cost  for  labor  and  material  per  linear  foot  of  trough 
about  $1.14.  When  the  price  of  labor  or  material  is  higher,  the  cost  will 
naturaly  be  greater,  and  vice  versa.  The  cost  of  the  stanchions  and  pipe  work 
is  about  $8.00  per  stall,  but  this  price  varies  with  the  local  market  and  the 
kind  of  stanchion  bought. 


Template,    of  //n  boards 


I  In  boards 

'/?.  C/eate 


Fig.  27.     Forms  for  Concrete  Trough. 


The  forms  for  a  trough  are  very  simple.  Two  forms  and  a  screed  or  templet 
are  all  that  is  required  (see  Fig.  27).  Oil  the  foms  thoroughly,  then  set  up 
the  front  and  back  forms  as  shown  and  brace  them  well.  Plaster  the  forms 
with  a  i -inch  coat  of  one  part  " ATLAS"  Portland  Cement  to  one  and  one-half 
parts  of  sand,  and  before  this  has  begun  to  stiffen  place  the  concrete.  It  is 
absolutely  necessary  that  the  mortar  finish  does  not  set  before  placing  the 
concrete,  for  otherwise  there  will  be  no  bond  between  the  body  of  the  concrete 
and  the  mortar  face,  which  will  be  sure  to  crack  off,  especially  if  kicked  or 
jarred.  The  screed  or  templet  is  cut  from  boards  nailed  together,  as  shown  in 
the  figure,  and  is  used  to  screed  off  the  concrete  and  make  it  the  desired  shape. 
The  reinforcement  and  the  pipes  for  the  stanchions  are  placed  as  shown. 

85 


FLOORS. 

CELLAR  FLOORS.  Cellar  floors  may  be  laid  without  foundations,  except 
in  places  where  there  is  danger  of  frost  getting  into  the  ground  below  the  floor. 
The  dirt  should  be  evened  off  and  tamped  hard,  and  the  concrete,  one  part 
"ATLAS"  Portland  Cement,  two  and  one-half  parts  clean,  coarse  sand  and 
five  parts  broken  stone,  spread  over  the  surface  in  one  continuous  slab  3  inches 
to  4  inches  thick  and  lightly  tamped  to  bring  the  water  to  the  surface,  and 
screeded  with  a  straight  edge  resting  upon  scantlings  placed  about  12  feet 
apart.  The  scantlings  are  then  withdrawn  and  their  places  filled  with  con- 
crete. No  finishing  coat  is  needed  unless  the  floor  is  to  have  excessive  wear. 
The  surface  of  the  concrete,  however,  should  be  troweled  as  soon  as  it  has 
begun  to  stiffen.  Joints  about  12  feet  apart  should  be  made  if  the  surface  is 
more  than  500  feet  long,  or  if  it  is  to  be  subjected  to  extreme  temperatures. 
(See  "Side  Walks,"  p.  75.) 


CONCRETE  FLOOR  IN  COW  STABLE  AT  ST.  CHARLES,  ILL. 

BARN  FLOORS.  Barn  floors  are  laid  in  the  same  manner  as  sidewalks.  The 
thickness  of  the  porous  sub-base  varies  with  conditions,  but  generally  6  to  12 
inches  is  sufficient.  The  floor  itself  should  be  about  4  inches  thick,  of  concrete 
in  proportions  one  part  "ATLAS"  Portland  Cement,  two  and  one-half  parts 

86 


INTERIOR  VIEW  OF  CARRIAGE  HOUSE  AT  WASCO,  ILL. 


FLOOR  OF  HORSE  BARN  AT  HOMER,  ILL. 

(This  floor  is  a  good  illustration  of  the  durability  of  concrete  floors.  It  is  40  x  60  feet,  and  although  it  has  been 
in  service  over  five  years,  no  cracks  of  any  kind  are  visible.  This  floor  was  made  of  one  part  "ATLAS  Portland 
Cement,  two  parts  sand  and  four  parts  stone,  and  surfaced  with  a  mortar  of  "ATLAS"  Portland  Cement  and  sand.) 

87 


clean,  coarse  sand,  and  five  parts  screened  gravel  or  broken  stone,  and  be 
finished  before  the  concrete  has  set  with  a  i-inch  mortar  surface  of  one  part 
"ATLAS"  Portland  Cement  to  one  and  one-half  parts  clean,  coarse  sand. 

The  surface  of  the  floor  should  have  sufficient  slope  to  carry  liquids  to  the 
drains,  and  in  order  to  prevent  the  animals  from  slipping  the  floor  may  be 
scored  or  grooved  into  blocks  before  the  concrete  has  hardened.  These  sec- 
tions may  be  about  6  inches  square. 

Some  builders  make  a  practice  of  waterproofing  the  stable  floor.  This 
is  not  necessary  in  most  cases,  but  where  there  is  any  great  danger  of  the 
ground  water  causing  the  barn  to  become  damp,  the  floor  should  be  laid  as 
follows : 

Place  a  2-inch  layer  of  concrete,  mop  on  a  3-ply  layer  of  tar  and  felt  water- 
proofing, and  then  upon  this  the  rest  of  the  concrete. 


CONCRETE  FEEDING  FLOOR  AND  WATERING  TROUGH  AT  EAST  NORWICH,  L.  I. 


FEEDING  FLOORS.  The  immense  advantage  of  concrete  feeding  floors 
over  the  old  method  of  placing  fodder  on  the  ground  is  apparent  to  all  who 
have  given  the  subject  any  thought. 

88 


Feeding  floors  should  be  built  the  same  as  sidewalks  (see  Walks).  The 
finishing  coat  is  optional,  although  it  has  the  advantage  of  being  much  easier 
to  keep  clean.  Many  farmers  prefer  an  unfinished  surface  on  account  of  its 
giving  cattle  a  firmer  footing  in  slippery  weather. 


o 

§  H 
s 


fc 


W7Ft. 


Mixing  Room 
Hay  Barn 

Feed  Room 


—  4QrJ.4~— 


Mi/king  Barn 
52.  Cows 


Cess  F}ool 

/-% 

Dairy  Building         -  \ 

^•'-'~"»  \  x^  V  ' 


I    I    1     I    I    ||    I    I    I     I    I    I    I'  MM     |    |    |    |    |    I    II    III 


Barn  SSCotvs 


•"""jl  A/a/TyeASfi^^ 

Wf    i  i  i  I  I  M  M  I  I  I  I  i!  M  I  I  I  I  i  i  M  I  I  I  I  I 


Total  length  254  ft. 


Fig.  28.     Plan  of  the  Farm  Building  at  the  New  York  Catholic  Protectory, 

Somers  Center,  N.  Y. 


RUNWAYS  FROM  STABLES. 

To  construct  a  runway  from  a  stable  make  up  two  or  three  batches  of 
concrete  in  proportions  one  part  "ATLAS"  Portland  Cement  to  two  parts 
sand  to  four  parts  gravel  or  broken  stone,  spread  it  in  place,  and  roughly 
trowel  the  surface.  If  a  fine,  smooth  surface  is  desired,  it  may  be  built  like  a 
sidewalk  (see  p.  75)  with  a  4-inch  base  of  concrete  and  one  inch  wearing 
surface  of  mortar  of  one  part  "ATLAS"  Portland  Cement  to  two  parts  sand. 
If  the  runway  is  built  on  a  slope  which  consists  of  filled  ground,  care 
must  be  taken  to  see  that  the  fill  is  well  tamped  and  not  liable  to  settle.  If 
there  is  any  danger  of  the  filling  settling  from  under  the  runway,  it  must  be 
designed  as  a  flat  slab.  In  this  case  the  thickness  of  slab  and  amount  of 
reinforcement  necessary  for  the  width  and  span  of  the  runway  can  be  taken 
directly  from  the  table  on  page  30,  using  the  heaviest  loading.  For  example, 
if  the  length  to  be  supported  is  8  feet,  place  ^2-inch  rods  in  bottom  of  slab, 
7*/2  inches  apart. 

89 


DRAINS. 

Since  well-made  concrete,  after  it  has  hardened,  is  not  injured  by  manure, 
concrete  is  being  used  to  replace  wooden  or  masonry  drains  which  are 
continually  rotting  or  leaking. 

Drains  may  be  made  either  in  place,  or  tile,  described  below,  may  be  used. 
In  any  case  lay  the  drain  with  enough  slope  to  flush  properly,  and  if  it  is  to 
receive  material  liable  to  clog,  make  it  open  or  with  a  removable  cover. 


INTERIOR  VIEW  OF  BARN  AT  EAST  NORWICH,  L.  I. 

To  make  a  drain  in  place,  dig  a  trench  on  the  proper  slope.  Set  sections 
of  form  the  shape  of  the  inside  of  the  drain  so  that  the  concrete  will  be  3  or  4 
inches  thick.  Pour  the  concrete,  mixed  in  proportions  one  part  "ATLAS" 
Portland  Cement  to  three  parts  coarse  gravelly  sand,  into  the  trench  under 
the  form.  Remove  the  form  when  the  concrete  has  hardened  for  about  one 
or  two  hours,  and  gently  trowel  the  surface  to  make  it  smooth  and  bring  the 
cement  to  the  surface. 

If  the  drain  is  to  have  lids,  the  concrete  of  the  sides  is  left  down  so  as  to 
leave  room  for  the  lid  and  have  the  top  sunk  about  %  inch  below  the  level  of 
the  floor. 

90 


TILE    DRAINS 

Concrete  land  tile  drains,  when  made  of  one  part  "ATLAS"  Portland 
Cement  to  three  parts  clean,  coarse  sand  which  has  been  sifted  through  a 
^2-inch  mesh  screen  and  of  a  soft,  mushy  consistency  like  mortar  used  for 
laying  brick,  can  be  depended  upon  to  resist  the  chemical  action  of  even  the 
most  alkaline  ground  water.  The  tile  may  be  made  12  or  18  inches  long,  and 
the  inside  diameter  anywhere  from  4  to  12  inches. 

The  forms  for  making  concrete  land  tile  are  simple  and  inexpensive.  One 
or  two  sets  of  forms  with  four  or  six  tile  each  may  be  made  so  that  they  can 


MOLDING  TILE  DRAINS 

be  filled  every  morning,  and  in  this  way  enough  tiles  can  be  soon  on  hand  to 
drain  a  large  acreage  of  land.  The  concrete  tile  should  be  made  with  a 
circular  bore,  and  may  be  either  circular  or  square  on  the  outside.  A  photo- 
graph of  a  tier  of  four  forms,  with  two  of  the  tile  on  a  board,  is  shown  above. 
Use  ordinary  stove  pipe  of  the  required  diameter  for  the  inside  mold;  this 
should  project  far  enough  above  the  top  of  the  wood  form  so  that  a  good  grip 
can  be  had  on  it  in  order  to  remove  it  from  the  concrete.  If  desired, 
holes  can  be  punched  through  the  stove  pipe  near  the  top  and  a  rod  placed 
through  these  holes  in  order  to  more  easily  draw  the  pipes.  To  keep  the 

91 


pipes  in  place  when  pouring  the  concrete  for  each  tile,  drive  four  nails  in  the 
floor  or  platform  on  which  the  tile  are  to  be  cast,  leaving  them  projecting  so  as 
to  locate  the  end  of  the  pipe  and  keep  it  from  getting  out  of  position  but  yet 
not  hindering  its  removal.  The  stove  pipes  must  be  thoroughly  cleaned  and 
greased  each  time  they  are  used,  and  must  not  be  dented  or  have  any  irregu- 
larities on  them  to  make  them  catch. 

As  shown  in  the  photograph,  the  wood  partitions  are  permanently  attached 
to  one  of  the  long  sides,  but  the  other  side  is  only  nailed  on  temporarily  and 
the  heads  of  the  nails  left  so  that  they  can  be  readily  withdrawn  with  a  claw 


MANURE  PIT  AT  GEDNEY  FARMS,  WHITE  PLAINS,  N.  Y. 

hammer  and  without  jarring  the  forms  unnecessarily.  The  wood  partitions 
are  spaced  far  enough  apart  so  that  there  is  one  inch  of  concrete  between 
stove  pipe  and  the  wood,  hence  make  the  distance  between  the  sides  equal  to 
the  diameter  of  the  stove  pipe,  plus  2  inches.  In  order  to  readily  remove  the 
wood  forms,  clean  and  oil  them  thoroughly  before  each  time  using.  Mix  the 
concrete  to  proportions  and  consistency  given  above  and  place  in  the  mold, 
ramming  with  a  stick.  The  time  to  remove  the  stove  pipe  core  varies  with 
the  wetness  of  the  mix  and  the  temperature,  but  it  should  be  pulled  as  soon 
as  the  top  of  the  concrete  begins  to  harden,  which  generally  is  from  one-half 
to  one  hour ;  if  left  too  long  it  is  very  hard  to  get  them  out.  The  outside  forms 

92 


can  usually  be  removed  after  two  or  three  hours,  or  may  be  left  until  the  next 
morning.  To  remove  the  wood  forms,  pull  the  protruding  nails  with  a  claw 
hammer,  and  carefully  remove  this  side.  Place  this  sideboard  back  again  in 
position,  and  carefully  turn  the  whole  tier  on  the  side.  Next  draw  out  the 
other  side  with  the  partitions  attached.  If  any  of  the  forms  stick,  they  can 
generally  be  started  by  tapping  them  lightly  with  a  hammer;  this  applies  as 
well  to  the  stove  pipe  cores.  Scrape  the  form,  carefully,  re-oil,  attach  the  long 
side  and  they  are  ready  for  a  second  filling. 

To  save  material  the  outside  of  the  tile  may  be  made  round  or  octagonal. 
For  the  latter  tack  triangular  strips  in  all  corners  of  the  mold. 


'f&3££&£-ji*i&*^t£l:. 


-»HH) 


T^?>fe 


Cpncrete,  D 


6/7. 


^•^^•Sr?*?:?-^^*^:^ 


Plan 


am 


iin.  steel  bars 
2.4/n.  on  centers 


din. 


£//7.  steel  bars  ^ 
6ec//o/?  of  drain 


<D 


f-3//7.  chestnut  plank 


4-/n.  /and  tile. 
/v///;  cottars 
for  outflow 


vSec//o/7    on  J/ne  A  A 
Fig.  29.     Concrete  Cess  Pool  and  Drains  at  New  York  Catholic  Protectory, 

Somers  Center,  N.  Y. 


93 


CESS    POOLS. 

A  cess  pool  for  either  a  house  or  a  barn  may  be  made  in  the  manner 
described  for  cisterns  on  page  119.  A  single  chamber  may  be  made  with 
over-flow  drains  laid  with  loose  joints  and  leading  under  the  surface  of  the 
ground  so  as  to  fertilize  the  lawn  or  garden. 

The  cess  pool  shown  in  Fig.  29  is  built  in  several  sections  so  that  the  manure 
may  settle  and  overflow  into  the  series  of  tanks.  The  sewage  from  the  drains 
empties  into  the  first  tank  where  the  heavy  material  settles,  leaving  the  water 
on  top.  When  the  water  level  rises  up  to  the  outlet  of  the  pipes  leading 


PUMP  HOUSE  AT  GEDNEY  FARMS,  WHITE  PLAINS,  N.  Y. 

from  the  first  to  the  second  chamber,  the  cleaner  water  is  drained  into  the 
second  chamber,  leaving  the  heavy  material  in  the  first.  This  same  process 
takes  place  in  each  of  the  other  three  chambers,  the  water  finally  draining  into 
the  concrete  tile  drains,  and  being  distributed  by  them  over  a  considerable  land 
area.  The  cess  pool  is  covered  with  a  chestnut  plank  cover  so  as  to  facilitate 
cleaning  if  this  ever  became  necessary.  A  5-inch  concrete  slab  reinforced  in 
the  bottom  with  ^-inch  rods  placed  6  inches  apart  might  be  used  instead, 
leaving  openings  in  it  for  trap  doors. 

94 


BOX    STALLS. 

Concrete  box  stalls  offer  a  great  advantage  over  stalls  of  other  material, 
for  they  are  warmer  in  winter  and  cooler  in  summer,  and  thus  help  to  prevent 
horses  becoming  restive  and  ill-tempered.  They  may  be  built  of  concrete  one 
part  "ATLAS"  Portland  Cement  to  two  and  one-half  parts  clean,  coarse  sand 
to  five  parts  broken  stone  or  screened  gravel,  and  should  have  walls  4  inches 
thick  and  reinforced  as  described  in  the  wall  specifications.  The  surface  can 
be  finished  off  the  same  as  outer  walls. 


BOX  STALLS  AT  WESTWOOD,  N.  J. 

VENTILATION. 

Concrete  barns,  like  houses,  are  built  either  with  a  single  solid  wall  or  with 
a  hollow  wall.  Each  type  offers  advantages  and  disadvantages.  For  in- 
stance, it  is  easier  and  cheaper  to  build  a  single  wall  on  account  of  having  no 
core  to  make  or  handle;  but,  on  the  other  hand,  these  openings  between  the 
walls  may  be  utilized  for  the  air  ducts  or  vents  through  which  the  ventilation 
in  the  barn  is  taken  care  of. 

In  designing  a  barn  it  is  of  the  utmost  importance  to  secure  perfect  ven- 
tilation, and  this  means  (i)  a  constant  change  of  air;  (2)  the  introduction  and 

95 


distribution  of  fresh  air  without  drafts;  (3)  the  introduction  of  outside  air, 
but  not  at  the  expense  of  the  proper  temperature,  and  (4)  the  removal  of  foul 
air  without  condensation. 

The  intake  registers  for  the  removal  of  the  foul  air  should  be  placed  in  the 
walls  near  the  floor.  The  foul  air  passes  from  the  registers  through  the  hollow 
spaces  in  the  walls  and  from  there  into  the  chimney.  The  chimney  is  best 
located  near  the  center  of  the  barn,  and  should  be  high  enough  to  extend  above 
the  roofs  of  any  nearby  building.  The  fresh  air  should  be  admitted  by  registers 
located  near  the  ceiling.  The  air  near  the  ceiling  is  usually  the  warmest; 
hence,  the  fresh  air  is  heated  somewhat  before  striking  the  cattle. 


PIGGERY  AT  GEDNEY  FARMS,  WHITE  PLAINS,  N.  Y. 

HOG    PENS. 

To  construct  a  concrete  hog  pen  excavate  a  trench,  the  size  and  shape 
desired  for  finished  pen,  10  inches  wide,  and  to  a  depth  below  frost,  and  fill 
with  concrete  mixture,  one  part  "ATLAS"  Portland  Cement,  four  parts  clean, 
coarse  sand,  and  eight  parts  broken  stone  or  screened  gravel.  On  top  of  this 
foundation  build  a  wall  (See  "Walls"),  at  equal  distance  from  edge,  4  inches 
thick  and  4  feet  high,  reinforced  with  wire  fabric  or  else  with  ^4-inch  rods 
placed  about  18  inches  apart  both  ways.  The  reinforcement  must  be  care- 
fully bent  around  the  corners.  Proportions  of  wall,  one  part  "ATLAS" 
Portland  Cement,  two  and  one-half  parts  clean,  coarse  sand,  and  five  parts 
broken  stone. 


96 


HOG  HOUSE  AT  BRICELYN,  MINN. 


INTERIOR  OF  PIGGERY  AT  GEDNEY  FARMS,  WHITE  PLAINS,  N.  Y, 


97 


Space  for  a  gate  should  be  left,  and^a  trough  built  similar  to  the  one  shown 
in  picture  or  described  in  "Hog  Troughs." 

A  hog  house  can  be  added  by  building  another  wall  in  the  corner  and 
roofing  the  space  with  2^/2  inches  concrete,  one  part  "ATLAS"  Portland 
Cement,  two  parts  clean,  coarse  sand,  and  four  parts  broken  stone.  This  slab 
must  be  reinforced  with  wire  mesh  or  steel  rods  of  size  and  spacing  given  in 
Table  for  Designing  Reinforced  Concrete  Beams  and  Slabs.  Flooring  may  be 
put  in  same  as  in  "Cellar  Floors"  (see  page  86). 


BOTTLING  ROOM  IN  DAIRY  HOUSE  AT  BROOKSIDE  FARMS,  NEWBURGH,  N.  Y. 


DAIRIES. 

The  dairy  may  be  connected  by  a  passage  way  with  the  barns  or  may  be 
in  a  building  by  itself.  In  either  case,  concrete  had  best  be  used  throughout 
for  the  various  rooms :  the  receiving  room,  the  bottling  room,  the  closets,  the 
refrigerator,  the  cold  storage  room,  the  shower  baths  and  the  clothes  closet; 
also  for  all  the  various  accessories,  such  as  the  troughs  for  the  milk  cans  and 
bottles. 


28  BY  30-FOOT  REINFORCED  CONCRETE  MILK  HOUSE  AT  BEACH  FARM  DAIRY,  AT  COLDWATER,  MICH. 


WELL  AND  CELLAR  AT  MARSHFIELD,  MO. 
99 


ICE  BOXES. 

Since  concrete  is  a  poor  conductor  of  heat  and  cold,  it  is  a  good  material 
for  an  ice  box.  It  may  also  readily  be  made  with  one  or  two  air  spaces  in 
the  walls  so  as  to  make  an  economical  storage  box.  Ice  boxes  are  sometimes 
built  as  a  part  of  a  new  building,  and  sometimes  are  built  onto  an  old  building. 
An  ice  box  is  not  in  the  least  affected  by  the  hard  usage  it  receives  by  having 
heavy  milk  cans  thrown  against  it. 


Fig.  30. 


Lorry  if  udinal  v5ec//c?/7 
Solid  Wall  Concrete  Ice  Box. 


An  ice  box  should  be  made  in  the  place  where  it  is  to  set,  as  it  will  be 
too  heavy  to  move.  Build  outside  forms  of  i-inch  tongued-and-grooved  and 
planed  boards.  Cleat  these  lightly  together  and  run  a  brace  back  to  hold  in 
place.  Make  a  light  box  or  use  one  already  made  for  the  inside  forms,  oiling 
or  greasing  it  well  before  placing  the  concrete.  Make  the  wall  8  inches  thick 
if  one  air  space  is  required,  or  10  inches  thick  for  two  air  spaces.  To  form  the 
air  space,  place  2-inch  plank  on  end  2  inches  from  the  form  and  in  pairs  so 
that  each  thickness  of  wall  will  be  2  inches  and  these  2-inch  walls  will  be  con- 

100 


INTERIOR  OF  CONCRETE  ICE  BOX  AT  BROOKSIDE  FARMS,  NEWBURGH,  N.  Y. 


CONCRETE  ICE  BOX  IN  A  DAIRY  AT  CHICAGO,  ILL. 
101 


nccted  by  sabout  4;  inches  of  concrete  at  the  ends  of  each  pair  of  plank.  By 
greasing  the  plank  thoroughly,  they  may  be  pulled  out  after  the  concrete  has 
began1  t'o  stiffen.  The  time  for  doing  this  will  be  about  an  hour  after  the  con- 
crete is  placed  if  it  is  made  about  the  consistency  of  mortar  for  laying  brick, 
or  about  two  hours  after  placing  if  it  is  made  thinner  than  this.  Pull  plank 
just  as  soon  as  the  surface  of  the  concrete  has  dried  off.  Leave  the  inside  and 
outside  forms  in  place  for  two  or  three  days.  To  furnish  a  place  for  a  double 
cover,  which  should  always  be  used  with  a  double  wall,  make  the  inside  sec- 
tion of  wall  lower  than  the  outside,  as  shown  in  Fig.  31.  There  should  be 
from  5/2  inch  to  i  inch  space  between  the  two  wood  covers.  The  hollow 
spaces  in  the  walls  may  be  filled  either  with  cork  or  mineral  wool,  which  helps 
considerably  to  keep  the  inside  of  the  ice  box  at  a  low  temperature  with  the 
least  amount  of  ice. 

Double  Cover 

•i 

2.in.x8in.  PJank 

planed  on  all  <side>s 


Fig.  31.     Hollow  Wall  Concrete  Ice  Box. 

In  Fig.  30  is  shown  an  ice  box  in  which  two  sides  have  a  taper  so  as  to 
catch  the  wood  trays.  The  other  two  sides  need  not  be  tapered.  The  cover  is 
made  in  two  sections  so  that  only  one  need  be  removed  in  order  to  place  or 
take  anything  from  the  trays.  The  bottom  of  the  box  should  be  made  sloping 
toward  a  drain  pipe,  which  may  be  fitted  with  an  elbow  and  an  upward  bend 
which  fills  with  water  and  traps  the  air  from  entering  the  ice  box,  while  it 
allows  the  water  from  the  melting  ice  to  drain  from  the  box. 


1 02 


SILOS. 

A  silo,  which  is  a  tank  or  chamber  for  preserving  fodder  or  ensilage  by  the 
exclusion  of  air  and  water,  is  a  practical  necessity  on  every  farm. 

Concrete  silos  are  without  question  the  most  satisfactory,  for  they  are 
water-tight,  practically  air-tight  and  vermin  or  rat-proof;  they  cannot  shrink, 
rot,  rust  or  burn  up;  they  will  not  blow  over  on  account  of  their  weight  nor 
collapse  when  empty.  Concrete  is  a  good  non-conductor  of  heat  and  cold  and 


ONE  OF  THE  SILOS  AT  GEDNEY  FARMS,  WHITE  PLAINS,  N.  Y. 

the  temperature  inside  such  a  silo  will  be  fairly  uniform  so  that  the  ensilage 
will  never  freeze  to  any  extent. 

Silos  are  generally  made  circular,  and  the  height  may  be  about  two  or 
three  times  the  diameter. 

There  are  three  ways  of  building  concrete  silos:  With  monolithic  or  solid 
walls ;  with  hollow  monolithic  walls ;  and  with  concrete  block  walls. 

Concrete  silos  are  more  economical  than  wood  because  of  their  durability. 
The  expense  varies,  of  course,  with  the  prices  of  the  ingredients  composing 
the  concrete  and  the  cost  of  the  form  work.  The  cost  of  the  gravel  and  sand 
is  generally  small,  for  there  are  comparatively  few  farms  without  a  gravel  pit 

103 


suitable  for  making  good  concrete;  hence,  it  is  in  the  handling  of  these 
materials  and  the  making  of  the  forms  that  the  principal  outlay  is  involved. 
A  reinforced  silo  can  be  built  cheaper  than  one  which  is  not  reinforced, 
because  of  the  thinner  walls  which  can  be  used. 

A  design  for  forms  and  staging  for  a  concrete  silo  is  shown  in  Fig.  32. 
The   table   gives   the   necessary   data   for   constructing   silos   of   different 
heights  and  diameters. 


Fig.  32. — Forms  and  Staging  for  Silos. 
104 


DATA  FOR  REINFORCED  CONCRETE  SILOS. 

(Including  6-Inch  Floor) . 
Proportions:     1  Part  "Atlas"  Portland  Cement  to  2  Parts  Sand  to  4  Parts  Gravel  or  Stone 


HORIZONTAL 

REINFORCEMENT 

PI  eight 

Inside 
Diameter 

Thickness 
of   Wall 

Cement 

Sand 

Stone 

Size 

Spacing 
C.  to  C. 

Feet 

Feet 

Inches 

Inches 

Inches 

Bbl. 

Cu.   Yd. 

Cu.  Yd. 

10 

5 

6 

1A 

12 

6% 

2 

4 

10 

10 

6 

H 

12 

isy2 

4 

8 

15 

5 

6 

X 

12 

91-.; 

3 

6 

15 

8 

6 

% 

12 

14^ 

4 

8 

15 

12 

6 

*/8 

12 

24 

-  6M 

13 

20 

8 

6 

y8 

12 

19K 

10 

20 

12 

6 

y* 

12 

29y2 

8 

16 

20 

15 

6 

3/0 

12 

38 

10 

20 

25 

10 

6 

1A 

12 

27^ 

7>^ 

15 

25 

15 

6 

1A 

12 

45 

12 

24 

25 

20 

6 

1A 

12 

62 

16^ 

33 

30 

10 

7 

>2 

12 

37 

10 

20 

30 

15 

7 

1A 

12 

58 

1  5  \-:t 

31 

30 

20 

7 

y* 

12 

80                    22'K 

45 

40 

15 

8 

1A 

12                  80                    22'^ 

45 

40 

20 

8 

y* 

12 

114                    30  U                61 

40                                         §__L_M 

12          1      147                    38^                77 

Place  vertical  rods  same  size  as  horizontal,  2  Yi  feet  apart. 

A  cubic  yard  is  about  1J  single  load  or  f  of  a  double  load. 

The  method  of  laying  out  the  curves  in  order  to  make  a  section  of  the 
form  for  a  silo  shown  above  is  given  in  Fig.  33. 

The  complete  circles  can  be  laid  off  in  this  manner  on  any  level  piece  of 
ground  or  on  a  barn  floor. 

After  laying  out  the  circles,  divide  them  into  a  number  of  equal  parts  in 
order  that  the  sections  shall  be  alike,  eight  divisions  generally  being  the  most 
convenient,  for  then  the  sections  are  not  too  large  to  handle  easily,  nor  too 
small,  making  too  many  in  number.  Make  all  the  joints  between  the  sections 
on  lines  with  the  center  of  the  silo  except  one  inside  joint,  which  is  cut  on  an 
angle,  as  shown  in  the  drawing,  in  order  to  permit  removing  the  inner  forms. 
This  section  which  is  cut  at  an  angle  is  placed  last  and  removed  first. 

The  curved  boards  for  the  frames  of  the  form  sections  can  be  cut  either 
from  one  wide  plank,  as  shown  in  Fig.  33,  or  from  two  narrow  planks  which 
are  tacked  together.  The  frames  may  be  covered  either  with  sheet  iron  or 
with  thin  boards  3  or  4  inches  wide  nailed  endwise  to  the  frame. 

The  forms  can  be  made  also  by  riveting  angle  irons  to  the  sheet  iron  to 
stiffen  it  instead  of  the  wood  shapes.  While  the  metal  form  is  more  expensive 
than  wood,  if  a  number  of  silos  are  to  be  built,  the  first  cost  of  the  forms  can 
be  larger,  because  it  is  divided  among  several.  One  man  making  a  form  of 
this  type  can  rent  it  to  his  neighbors,  and  in  this  way  more  than  pay  for  the 
extra  money  spent  in  making  the  forms. 

105 


Fig.  33. — Method  of  Laying  Out  Silo  Forms. 


Excavate  the  earth  to  a  depth  below  frost,  which  in  the  Northern  and 
Middle  States  is  about  4  feet,  while  in  the  Southern  States  3  feet,  or  even  2 
feet,  may  be  sufficient  and  of  the  required  diameter.  If  the  earth  is  hard  and 
will  stand  alone  sometimes  it  is  only  necessary  to  excavate  to  the  outside 
diameter  of  the  silo.  In  other  cases  the  diameter  of  the  circle  for  excavating 
must  be  4  or  5  feet  larger  than  the  outside  diameter  of  the  silo,  so  as  to  allow 
for  a  2  or  2^-foot  trench  to  make  room  for  placing  and  removing  the  outer 
form.  Grease  the  forms  thoroughly.  A  mixture  of  fat  or  lard  with  kerosene 
makes  a  good  grease  for  oiling  the  forms. 

Care  must  be  taken  in  placing  the  reinforcement.  Locate  the  horizontal 
reinforcement  by  marking  on  one  or  two  of  the  4  by  4-inch  upright  studs  of 
the  scaffolding  the  location  of  all  the  rods;  then  there  will  be  no  question 
whether  or  not  the  reinforcement  is  in  the  correct  position. 

1 06 


Before  mixing  the  concrete,  bend  the  horizontal  rods  into  rings  so  that  they 
will  go  in  the  middle  of  the  wall.  Lap  the  ends  2  feet.  To  find  the  length  of 
rod  to  go  around  a  silo,  add  to  the  inside  diameter  the  thickness  of  one  wall 
and  multiply  this  sum  by  3  1/7.  This  gives  the  circumference  of  the  center 
line  of  the  wall.  If  the  length  of  this  circumference  is  not  too  long  for  one 
rod,  add  2  feet  for  the  lap.  If  two  rods  are  necessary,  add  2  feet  for  each  lap ; 
that  is,  make  every  rod  2  feet  longer  than  is  required  for  the  actual  circum- 


CONCRETE  SILO  AT  CHARLOTTES VILLE.  VA. 


ference.  By  placing  the  inside  form  of  the  silo  first,  the  reinforcement  may 
be  set  in  advance  of  the  concreting,  the  horizontal  rods  being  tied  to  the 
verticals  by  soft  wire  about  1/16  inch  diameter.  This  is  a  better  way  than  to 
place  the  horizontal  rods  as  the  concrete  is  being  laid.  The  table  gives  the 
distance  apart  of  the  horizontal  rods  at  the  bottom  of  the  silo.  Increase  the 
spacing  slightly  toward  the  top  so  that  at  the  top  the  rods  are  double  the 
distance  apart  they  are  at  the  bottom. 

107 


Mix  the  concrete,  using  one  part  "ATLAS"  Portland  Cement,  two  parts 
clean  sand  and  four  parts  broken  stone  or  screened  gravel.  For  mixing  of  the 
concrete,  see  page  24.  Make  the  mixture  of  sloppy  consistency  about  like 
heavy  cream,  place  it  in  the  forms  and  ram  lightly  to  distribute  the  mortar 
and  drive  out  air  bubbles.  Before  removing  the  forms,  clean  off  the  top  of  the 
wall  with  a  stiff  wire  brush  or  an  old  horse  curry  comb,  and  raise  the  forms 
for  the  next  filling.  Before  placing  the  new  concrete,  wet  thoroughly  the  sur- 
face and  spread  a  ^-inch  layer  of  mortar  mixed  about  one  part  "ATLAS" 
Portland  Cement  to  one  part  sand  and  then  place  the  concrete.  Care  must  be 


CONCRETE  SILOS  AT  EAST  NORWICH,  L.  I. 

(The  dimensions  of  these  silos  are  as  follows:  Footing,  4  feet  below  ground;  20  feet  inside  diameter;  24  feet  above 
ground;  12-inch  walls  reinforced  vertically  with  1-inch  rods  4  feet  c.  to  c.  and  horizontally  with  J^-inch  rods  3  feet 
c.  to  c.  There  were  443  bags  of  "ATLAS"  Portland  Cement  used.) 

used  in  tamping  the  concrete,  not  to  push  the  rods  to  one  or  the  other  side  of 
the  form,  but  to  keep  them  in  the  center  of  the  wall. 

As  soon  as  the  forms  are  removed  roughen  the  inside  surface  by  scraping 
off  the  skin  of  cement  with  a  wire  brush  or  a  brick;  as  soon  as  the  walls  of 
the  silo  are  completed  wet  the  inside  surface  thoroughly  with  clean  water,  and 
plaster  it  with  not  over  a  i/i6-inch  coat  of  one  part  "ATLAS"  Portland 
Cement  to  one  part  clean,  coarse  sand,  screened  through  a  fine  screen.  Pro- 

108 


tect  the  surface  from  the  sun  and  wet  twice  a  day  for  seven  days.  It  is  very 
important  to  have  this  inside  surface  perfectly  smooth,  for  when  the  ensilage 
settles  after  being  packed,  any  roughness  of  the  walls  is  liable  to  cause  the 
cornstalks  to  catch  and  prevent  them  settling  evenly.  The  ensilage  around  the 
air  space  thus  formed  becomes  moldy  and  must  be  thrown  away.  This  same 
thing  occurs  where  the  concrete  is  laid  with  too  little  water.  The  concrete 
then  is  porous  and  sucks  out  the  moisture  from  the  ensilage,  forming  a  dry 
skin  of  material  next  to  the  wall. 

Defa/f  of  Chufc  DC- 
fi very  on  Line  &-&. 


line. 


De~faif  of  Forms 
fbrms  4- 


— m--/r 


Fig.  34.    Details  of  Silo  Built  at  U.  S.  Soldiers'  Home,  Washington,  D.  C. 

The  outside  surface  of  the  silo  is  generally  good  enough  if  it  is  rubbed 
down  with  a  board  or  a  brick,  using  water  with  it,  immediately  after  taking  off 
the  forms  while  the  concrete  is  fairly  soft  so  as  to  take  off  the  joint  ridges 
and  leave  a  uniform  surface.  By  removing  the  forms  the  next  day  after  laying 
the  concrete,  it  is  possible  then  to  entirely  remove  the  skin  of  cement,  leaving 
the  sand  and  stone  exposed  enough  to  give  a  very  pleasing  finish. 

For  convenience  in  handling  the  ensilage,  it  is  well  to  leave  openings  or 
doors  about  20  inches  square  at  least  every  three  feet  on  one  side  of  the  silo. 

109 


Door  2.4x24>//7. 


ll-- 
II 
ll 

If-- 

1 
1 
1 

•    1 
1     1 
1    1 

| 

1 
1 
1 

:  ; 

i    . 

1 

1 

1 

i 

£ 

m 

IX^h 

--U-, 

1 

,L_ 

1 

1    1 

•  • 

i 

1 

1 

1 

^7 
1    i 

j 

35-    Door  for  Silo  at  East  Norwich,  L.  I.,  N.  Y. 


CONCRETE  SILO  FOUNDATION  AT  BRICELYN,  MINN. 
HO 


When  desired,  an  opening  20  inches  wide  may  be  left  the  entire  height  of  the 
silo  if  a  part  of  the  horizontal  reinforcement  is  run  across  the  opening  to 
strengthen  it;  this  opening  is  to  be  closed  by  a  series  of  wooden  doors.  A 
good  design  for  a  door  or  a  series  of  doors  is  shown  in  Fig.  35. 

A  chute  running  to  the  full  height  of  the  silo  has  sometimes  been  built 
around  these  doors  or  openings  being  constructed  simultaneously  with  the 


SILO  AT  SOUTH  CHARLESTOWN,  OHIO 

walls.  Make  the  walls  of  the  chute  4  inches  thick  and  reinforce  them.  A 
convenient  size  for  such  a  chute  is  about  4  feet  along  the  face  and  2^2  feet  at 
the  sides. 

One  method  of  building  a  chute  is  illustrated  in  Fig.  34.  The  chute  is 
made  of  1 2-inch  tiles  and  pipe,  each  length  being  24  inches.  Alternate  lengths 
of  plain  pipe  and  tiles  were  used  so  as  to  bring  the  openings  4  feet  apart. 

in 


HOLLOW  WALL  SILOS. 

If  it  is  desired  to  make  the  silo  with  a  hollow  wall,  the  construction  can 
be  made  similar  to  the  ice-box  walls  described  on  page  100.  The  inside  section 
of  the  wall  of  the  silo  is  made  the  thickness  required  in  the  silo  table,  page  105, 
and  the  other  walls  3  inches  thick  with  lighter  reinforcement.  Formerly  it 
was  thought  necessary  to  make  all  silos  of  hollow  wall  construction,  but  this 
is  now  practically  superseded  by  the  solid  wall  built  with  dense  wet  mixed 
concrete. 


STORAGE  WATER  TANK  AT  BOODY,  ILL. 

TANKS. 

Concrete  tanks,  if  properly  built,  are  superior  in  all  respects  to  any  other 
kind  of  a  tank  for  storing  water  or  grain.  They  are  easy  to  clean,  and  do  not 
rot  or  rust.  The  concrete  mixture  should  be  in  proportions  one  part 
"ATLAS"  Portland  Cement  to  one  and  one-half  parts  clean  but  rather  fine 
sand  to  three  parts  screened  gravel  or  broken  stone. 

A  tank  in  order  to  withstand  water  pressure  and  not  leak  is  best  built  by 
laying  the  concrete  without  stopping.  Even  then  there  are  other  essential 
things  which,  if  disregarded,  will  produce  a  leaky  tank.  The  concrete  must 
be  mixed  so  wet  that  it  will  flow  over  and  around  the  metal  reinforcement  and 
against  the  forms.  The  materials  for  the  concrete  must  be  very  carefully 
proportioned  and  the  stones  small  enough  to  pass  a  ^4-inch  mesh  screen.  A 

112 


concrete  made  by  using  very  clean  screened  gravel  makes  a  denser  concrete 
than  broken  stone;  it  flows  into  place  better  and  is  not  so  apt  to  have  voids 
and  stone  pockets  which  let  through  the  water. 

SQUARE  TANKS  (Small).  Square  tanks  do  not  stand  water  pressure  so 
well  as  round  because  the  sides  tend  to  bulge,  but  they  are  all  right  if  not 
more  than  4  feet  deep  and  8  feet  square.  Build  outside  forms  12  inches  wider, 


WATER  TANK,  NEAR  MORTON,  ILL. 

12  inches  longer  and  6  inches  deeper  than  the  inside  of  the  finished  tank.  Set 
mesh  reinforcement,  or  else  ^-inch  rods  running  both  ways  and  6  inches  apart, 
in  bottom  of  tank  and  the  reinforcement  given  for  a  5-foot  round  tank  in  the 
sides.  Allow  the  vertical  rods  to  project  down  to  the  bottom  and  the  bottom 
rods  to  project  up  into  the  sides.  Tie  horizontal  rods  to  vertical  by  i/i6-inch 
soft  wire.  Place  inner  form  4  inches  from  the  outside  form.  This  form  can 
rest  on  iron  pins  driven  into  the  ground.  Grease  forms  thoroughly.  Put 
concrete  into  forms  at  one  continuous  operation  so  that  there  will  be  no  joints 
between  courses,  making  it  of  the  consistency  of  heavy  cream.  As  the 
concrete  is  placed  in  the  bottom,  lift  the  reinforcement  a  little  to  allow  the 

"3 


concrete  to  get  in  under  it.  When  filling  the  wall  take  care  to  keep  the 
reinforcement  in  place.  By  working  carefully,  the  inside  form  may  be 
removed  as  soon  as  the  concrete  has  become  dry  on  top,  say,  in  two  or  three 
hours,  although  a  better  way  is  to  leave  it  for  two  or  three  days  and  knock 
the  form  to  pieces.  Leave  outside  form  in  place  for  three  or  four  days. 
After  the  concrete  has  set  and  the  forms  are  removed,  paint  inside  of  the  tank 
with  pure  cement  mixed  with  water  to  the  consistency  of  cream  and  brush  in 


WATER  TANK  AT  MORTON,  ILL. 

well.  This  should  prevent  any  leakage.  Protect  the  tank  from  the  sun  till 
ready  to  use  and  wet  two  or  three  times  a  day  for  a  week  after  removing  the 
forms.  Do  not  fill  with  water  until  tank  is  two  weeks  old. 

ROUND  TANKS.  Follow  exactly  the  same  methods  given  for  square  tanks, 
except  using  thicknesses  and  reinforcement  given  in  the  table.  Lay  out 
circular  forms  as  described  on  page  20  or  page  106.  Set  the  reinforcement  in 
place  and  pour  the  concrete  in  the  same  way  as  for  square  tanks. 

114 


WELL  HOUSE  WITH  HEAVY  CONCRETE  COLUMNS  FOR  SUPPORTING  STEEL  FRAME  OF  HIGH 
WATER  TANK  AT  COLUMBIA,  MO. 


WATER  TANK,  SO.  CHARLESTON,  O. 
115 


Tanks  sometimes  have  to  be  constructed  by  filling  one  or  two  sections  of 
forms  each  day,  letting  it  set  over  night  and  continuing  the  next  day.  This 
is  bad  practice  because  it  is  readily  seen  that  a  joint  is  formed  on  the  surface 
of  each  layer  of  concrete  which  is  placed  on  top  of  another  layer  that  has  set 
up  and  hardened;  to  make  the  joint  as  tight  as  possible  the  top  surface  of  the 
old  concrete  must  be  specially  treated.  The  operation  for  treating  this 
surface  is  as  follows:  Scrape  off  all  dirt  and  scum  from  the  old  surface,  pick 
it  with  a  pick  or  scrub  it  thoroughly  with  a  wire  brush  or  horse  curry  comb 
in  order  to  remove  all  surface  mortar  and  scum  and  leave  a  very  rough 


WATER  TANK  AT  BERRY  HILL,  L.  I.,  N.  Y. 

surface.  To  make  the  bond  between  this  cleaned  surface  and  the  new 
concrete,  wet  it  thoroughly,  soaking  it  well,  place  a  ^4-inch  to  ^-inch  layer 
of  one  part  "ATLAS"  Portland  Cement  to  one  part  sand,  or,  better  still,  a 
layer  of  pure  "ATLAS"  Portland  Cement  on  the  cleaned  surface,  and  before 
this  has  set  or  has  begun  to  stiffen  place  the  new  concrete  upon  it.  In  some 
cases  a  positive  bond  between  the  old  and  new  concrete  work  is  used  in 
addition  to  the  above  by  imbedding  in  the  top  of  the  last  mass  of  concrete 
laid  each  day  a  4  by  4-inch  piece  or  a  V-shaped  stick  of  timber.  This  timber, 
which  is  removed  the  next  morning,  will  form  a  groove  to  bond  the  new  and 
old  concrete  together. 

116 


If  the  tank  is  built  above  ground,  remove  sod  and  earth  until  good  firm 
material  is  reached.  Excavate  in  any  case  at  least  6  inches  below  the  bottom 
of  the  tank  and  build  foundation  6  inches  thick  of  screened  gravel  or  cinders 
or  crushed  stone,  spreading  in  4-inch  layers  and  ramming  hard.  Be  sure 
that  this  foundation  is  drained  so  that  the  water  cannot  collect  and  freeze  in  it. 

For  inlets  and  outlets  to  tanks  place  pieces  of  pipe  in  the  concrete  while 
it  is  being  deposited. 

Tanks  may  be  roofed  with  either  a  wooden  or  concrete  roof.  For  concrete 
lay  the  concrete  on  a  very  flat  slope  and  reinforce  it  as  described  in  the  table 
for  concrete  beams  and  slabs  on  pages  30  and  31.  A  wooden  roof  is  apt  to  be 
cheaper  and  will  answer  most  purposes. 

REINFORCEMENT    FOR    TANKS. 

The  table  which  follows  gives  a  list  of  sizes  of  steel  required  for  tanks  of 
several  different  dimensions,  allowing  ample  factor  of  safety.  It  is  extremely 
important  that  the  horizontal  steel  be  placed  exactly  as  given.  The  entire 
pressure  of  the  water  is  assumed,  according  to  the  very  best  practice,  to  be 
taken  by  the  steel,  as  concrete  is  not  reliable  in  tension  unless  reinforced. 
The  thickness  of  concrete  is  only  required  to  imbed  the  steel  and  to  make  the 
tank  water-tight,  and  should  vary  with  the  height  of  the  tank,  but  not  neces- 
sarily with  the  diameter.  A  minimum  thickness  of  4  inches  for  a  5-foot  tank, 
running  up  to  10  inches  for  a  tank  15  feet  deep,  is  suggested. 


(1) 

(2) 

(3) 

(4) 

(5) 

(6) 

(7) 

(8) 

Depth 

Diameter 

Thickness 
of 

Diameter 
Circumfer- 

Spacing 
Circumfer- 

Spacing 
Circumfer- 

Diameter 
Vertical 

Spacing 
Vertical 

Concrete 

ential  Rods 

ential  Rods 

ential  Rods 

Rods 

Rods 

at  Bottom 

at  Top 

Ft. 

Ft. 

Inches 

Inches 

Inches 

Inches 

Inches 

Ft. 

5     b 

Y       5 

6 

X 

6 

9 

% 

1^ 

5 

10 

6 

5/16 

6 

9 

Y% 

2  \'» 

10 

10 

8 

:>s 

6 

12 

•>8 

2  i-o 

10 

15 

8 

}4 

6 

12 

H 

3 

15 

10 

12 

1A 

6 

is 

H 

2H 

15 

15 

12 

'/& 

6 

15 

/'s 

3 

NOTE.— Bend  circumferential  rods  in  rings,  place  in  center  of  wall  and  lap  ends  2  feet, 
spacing  of  circumferential  rods  from  bottom  to  top. 


Increase,  gradually, 


GRAIN   ELEVATORS. 

Concrete  grain  elevators  of  immense  size  are  being  built  all  over  the 
country  by  the  railroads.  For  the  storage  of  grain  on  the  farm  or  in  a  village 
grain  elevators  can  be  built  like  silos,  and  the  descriptive  matter  and  amount 
of  reinforcement  under  silos,  pages  103  to  113,  will  apply.  An  elevator  built  in 
this  way  is  proof  against  rats  and  other  vermin,  and  is  water-tight. 

117 


CORN  CRIBS. 

The  waste  caused  each  year  by  rats  and  mice  in  corn  cribs  is  enormous. 
This  loss  can  be  prevented  by  constructing  the  entire  corn  crib  of  concrete,  as 
well  as  the  floor,  which  makes  it  also  fireproof. 

The  corn  crib  may  be  constructed  with  5  x  5-inch  concrete  posts,  spaced  4 
feet  on  centers,  and  extending  from  the  concrete  foundation  to  the  roof  plate, 
which  may  also  be  a  beam  of  concrete  tying  the  posts  together  and  supporting 
the  wooden  roof.  On  two  of  the  opposite  sides  of  the  posts  mold  a  slot  i  inch 
deep  by  2  inches  wide  its  entire  length.  The  sides  of  the  crib  may  consist  of 


40  BY  60-FOOT  STOREHOUSE  AT  LOWVILLE  N.  Y..  WITH  CONCRETE  PIERS 

a  series  of  slats  or  slabs.  Cast  or  mold  these  separately  2  inches  thick  by  5 
inches  high  by  3  feet  8  inches  long,  and  reinforce  with  two  %-inch  rods  in  the 
same  way  that  fence  posts  are  molded.  After  thoroughly  seasoning,  place 
the  slats  in  the  slots  in  the  posts  so  that  there  is  a  ^-inch  opening  between 
them.  To  accomplish  this  place  one  slat,  then  throw  some  mortar  in  the 
groove  in  the  post  on  top  of  it.  Place  the  next  slat,  and  push  it  into  the 
mortar  at  the  joint  so  that  a  ^2-inch  space  remains  between  the  two  slats. 
Continue  in  this  way  up  to  the  plate. 

The  mix  of  concrete  should  be  one  part  "ATLAS"  Portland  Cement  to 
two  parts  clean,  coarse  sand  to  three  parts  fine  screened  gravel,  or  one  part 
"ATLAS"  Portland  Cement  to  four  parts  unscreened  gravel  or  sand. 

118 


CISTERN. 

Make  a  circular  excavation  16  inches  wider  than  the  desired  diameter  of 
the  cistern,  or  allow  for  a  wall  two-thirds  the  thickness  of  a  brick  wall  that 
would  be  used  for  the  same  purpose,  and  from  14  feet  to  16  feet  deep.  Make 
a  cylindrical  inner  form  (see  Circular  Form)  the  outside  diameter  of  which 
shall  be  the  diameter  of  the  cistern.  The  form  should  be  about  9  feet  long 


CONCRETE  CISTERN  AT  ST.  CHARLES,  ILL. 

for  a  14-foot  hole,  and  n  feet  long  for  one  16  feet  deep.  Saw  the  form  length- 
wise into  equal  parts  for  convenience  in  handling.  Lower  the  sections  into 
the  cistern  and  there  unite  them  to  form  a  circle  (Fig.  No.  36),  blocking  up  at 
intervals  six  inches  above  the  bottom  of  excavation.  (Withdraw  blocking 
after  filling  in  spaces  between  with  concrete  and  then  fill  holes  left  by  blocking 
with  rich  mortar.) 

119 


Make  concrete  of  one  part  "ATLAS"  Portland  Cement,  two  parts  clean, 
coarse  sand  and  four  parts  broken  stone  or  gravel.  Mix  just  soft  enough  to 
pour.  Fill  in  space  between  the  form  and  the  earth  with  concrete,  and  puddle 
it  to  prevent  the  formation  of  stone  pockets,  using  a  long  scantling  for  the 
purpose  and  also  a  long-handled  paddle  for  working  between  the  concrete 
and  the  form.  To  construct  the  dome  without  using  an  expensive  form, 
proceed  as  follows :  Across  top  of  the  form  build  a  floor,  leaving  a  hole  in  the 
center  two  feet  square.  Brace  this  floor  well  with  wooden  posts  resting  on 
the  bottom  of  the  cistern.  Around  the  edges  of  hole,  and  resting  on  the  floor 


Fig.  36.     Concrete  Cistern. 

described,  construct  a  vertical  form  extending  up  to  the  level  of  the  ground. 

Build  a  cone-shaped  mold  of  very  fine  wet  sand  from  the  outer  edge  of 
the  flooring  to  the  top  of  the  form  around  the  square  hole  and  smooth  with 
wooden  float.  Place  a  layer  of  concrete  four  inches  thick  over  the  sand  so 
that  the  edge  will  rest  on  the  side  wall. 

Let  concrete  set  for  a  week,  then  remove  one  of  the  floor  boards  and  let 
the  sand  fall  gradually  to  the  bottom  of  the  cistern.  When  all  boards  and 
forms  are  removed  they  can  be  easily  passed  through  the  two-foot  aperture 
and  the  sand  taken  out  of  the  cistern  by  means  of  a  pail  lowered  with  a  rope. 
This  does  away  with  all  expensive  forms  and  is  perfectly  feasible.  The 


1 20 


bottom  of  the  cistern  should  be  built  at  the  same  time  as  the  side  walls  and 
should  be  of  the  same  mixture,  six  inches  thick. 

SQUARE    CISTERNS. 

Excavate  to  desired  depth  and  put  in  6  inches  concrete  floor,  one  part 
"ATLAS"  Portland  Cement,  two  parts  sand  and  four  parts  broken  stone. 
As  soon  as  practicable,  put  up  forms  for  8-inch  walls  (see  Walls)  and  build 
the  four  walls  simultaneously.  If  more  than  8  feet  square,  walls  should  be 
reinforced  with  a  woven  wire  fabric  or  steel  rods. 


CONCRETE  CISTERN  AT  MONROE,  N.  J. 

WELL    CURBS. 

Concrete  makes  the  best  well  curb,  as  it  keeps  out  the  surface  water  and 
is  easily  kept  clean. 

After  the  well  has  been  dug  to  the  desired  depth,  and  the  sides  properly 
braced  in  short  sections  so  that  the  earth  cannot  cave  in,  build  a  circular  form 
8  inches  smaller  than  the  diameter  of  the  hole,  and  4  feet  long.  (See  Circular 
Forms.)  Lower  to  the  bottom  in  sections  and  adjust  so  that  there  are  4 
inches  between  the  form  and  the  side  of  the  hole.  Place  concrete  mixture,  one 
part  "ATLAS"  Portland  Cement,  two  and  one-half  parts  clean,  coarse  sand 


SPRING  CURB  AT  MONROE,  N.  J. 


CURB  IN  INTERIOR  OF  SPRING  HOUSE  AT  LAKE  MASCOMA,  N.  H. 

122 


and  five  parts  broken  stone  or  gravel,  in  this  space.  To  allow  the  water  to 
get  into  the  well,  place  a  couple  of  pints  of  loose,  broken  stones  in  "pockets" 
every  few  feet  until  the  water  level  is  reached.  After  filling  the  form  to  the 
top  and  allowing  it  to  set  over  night,  or  until  the  concrete  will  bear  pressure 
of  the  thumb,  raise  it  3  feet,  brace  securely  and  repeat  until  ground  level  is 
reached.  A  slab  4  inches  thick  and  8  feet  square  should  be  built  around  the 
top  of  the  well,  first  replacing  surface  soil  with  a  layer  of  cinders  or  clean 
gravel,  well  rammed,  about  12  inches  thick. 


SPRING  CURB  AT  MONROE,  N.  J. 


ICE    HOUSES. 

There  has  been  considerable  discussion  as  to  whether  or  not  concrete  ice 
houses  are  a  success.  After  thorough  investigation  the  conclusion  has  been 
reached  that  there  are  none  better,  if  properly  built — i.  e.,  with  a  double  wall. 

Excavate  a  foot  below  the  desired  depth  and  put  in  a  layer  of  coarse 
gravel  or  broken  stone,  ramming  hard.  This  makes  a  good  floor 
and  leaves  plenty  of  drainage.  Set  up  forms  in  shape  finished  structure  is 
desired,  allowing  16  inches  for  a  wall,  and  build  foundation  one  part 

123 


ICE  HOUSE  AT  MONMOUTH,  ILL. 


ICE  HOUSE  AT  BABYLON,  L.  L 
124 


"ATLAS"  Portland  Cement,  three  parts  clean,  coarse  sand  and  six  parts 
broken  stone,  16  inches  wide  by  4  feet  deep,  or  below  frost.  The  wall  should 
be  built  as  shown  in  Hollow  Walls,  making  two  s-inch  walls  with  a  6-inch 
space,  each  reinforced  with  one-quarter-inch  rods  placed  12  inches  apart  in 
both  directions.  Mixture:  One  part  "ATLAS"  Portland  Cement,  two  parts 
clean,  coarse  sand  and  four  parts  broken  stone.  The  wall  should  be  built  in 
sections  about  2  feet  high  at  a  time,  and  the  outer  and  inner  walls  should  be 
bound  together  by  placing  galvanized  iron  strips,  one  inch  broad  by  one-sixth 


15  BY  20-FOOT  CONCRETE  ICE  HOUSE  ATTACHED  TO  COW  BARN  AT  LOWVILLE,  N.  Y. 

inch,  and  turned  up  about  an  inch  at  each  end  between  the  first  and  second 
section,  after  the  first  section  of  the  inner  form  has  been  removed.  These 
strips  will  not  only  strengthen  the  wall,  but  will  serve  as  a  convenient  footing 
for  the  second  tier  of  inner  forms,  etc.  The  ends  and  top  should  be  filled 
in  solid  to  the  depth  of  6  inches,  leaving  no  openings  for  the  air  to  circulate. 
The  roof  should  be  made  slanting,  and  after  the  lower  or  inner  side  is 
completed  5  inches  of  sand  may  be  placed  on  top  and  leveled  off.  The  upper 
or  outer  surface  of  the  roof  can  then  be  laid,  with  suitable  reinforcement, 
directly  upon  the  sand,  and  carefully  trowelled  as  soon  as  it  is  partly  set.  The 
sand  is  let  out  at  an  opening  left  for  the  purpose  at  the  sides  when  the  concrete 
has  dried  for  a  couple  of  weeks.  There  should  be  several  square  blocks  of 

125 


concrete  placed  so  as  to  connect  the  two,  and  a  strong  concrete  beam  should 
form  the  ridgepole.  All  openings  between  the  walls  and  roof  and  the  two 
layers  of  roof  should  be  sealed  up  solid,  so  as  to  give  a  dead  air  space  between 
them.  Shrinkage  cracks  are  liable  to  form  on  large  concrete  roof  surfaces 
so  that  if  a  surface  is  over  20  feet  square  it  should  be  covered  with  tar  and 
gravel  or  some  other  kind  of  roofing. 

For  a  small  house  the  dimensions  of  beams  and  slabs  for  roof  may  be 
obtained  from  table  of  Reinforced  Beams  and  Slabs,  but  for  a  large  house 
money  will  be  saved  and  safety  assured  by  consulting  an  engineer  or  architect 
experienced  in  concrete  design. 


ROOT  CELLAR  AT  KNOXVILLE,  IOWA 

ROOT    CELLARS. 

Root  cellars  are  usually  built  half  below  and  half  above  the  level  of  the 
ground.  Excavate  16  inches  below  the  desired  level  of  the  floor,  and  around 
the  sides  build  a  foundation  12  inches  broad,  one  part  "ATLAS"  Portland 
Cement,  three  parts  clean,  coarse  sand  and  six  parts  broken  stone  or  gravel. 
Remove  the  form  and  fill  between  the  foundations  to  a  depth  of  12  inches 
with  porous  material,  tamping  well.  On  this  build  a  floor  as  described  under 
Cellar  Floors,  p.  86.  On  the  foundation  and  at  equal  distance  from  either  edge 

126 


ENTRANCE  TO  ROOT  CELLAR,  UNDER  WAGON  HOUSE,  AT  U.  S.  SOLDIERS'  HOME, 

WASHINGTON,  D.  C. 


ROOT  CELLAR,  BABYLON,  L.  I. 
137 


erect  a  solid  wall  8  inches  thick  (see  Walls),  one  part  "ATLAS"  Portland 
Cement,  two  and  one-half  parts  clean,  coarse  sand  and  five  parts  cinders, 
broken  stone  or  gravel,  leaving  an  opening  at  one  end  for  the  steps  (see 
Steps).  Build  up  the  end  walls  so  as  to  form  a  point  in  the  middle  and 
high  enough  to  give  the  roof  a  sufficient  pitch  to  shed  the  rain. 

Near  the  top  at  each  end,  openings  for  windows  should  be  left  and  sash 
fitted  and  plastered  in  after  the  concrete  has  set  and  forms  have  been  removed. 

Bins  should  be  built  of  size  and  height  to  suit  convenience,  with  walls  4 
inches  thick  and  reinforced  with  one-quarter-inch  rods  placed  12  inches  apart 
horizontally  and  vertically. 


ROOT  CELLAR  AT  GLEN  COVE,  L.  I. 


If  a  concrete  roof  is  desired,  forms  should  be  erected  and  a  roof  3  inches 
thick  laid  on.  On  the  top  of  this,  and  before  the  concrete  is  dry,  a  layer 
one-quarter  inch  thick  of  one  part  "ATLAS"  Portland  Cement  and  one  part 
sand  should  be  placed,  trowelled  when  partially  set,  and  smoothed  with  a 
wooden  float.  This  surface  must  be  wet  three  times  a  day  for  a  week  or  two. 
Forms  should  not  be  removed  from  roof  for  at  least  three  weeks. 

Should  the  roof  be  sufficiently  long  to  require  support  other  than  the 
concrete  beam  that  forms  the  ridge  pole  (see  section  on  Reinforced  Concrete), 
posts  can  be  built  in  place  8  inches  square. 

128 


Roof  and  steps  should  be  reinforced  with  a  woven  wire  fabric  or  with 
steel  rods. 

MUSHROOM    CELLARS. 

Mushroom  cellars  should  be  built  at  least  two-thirds  below  the  level  of  the 
ground  to  obtain  the  best  results. 

Excavate  to  the  desired  depth,  and  around  the  edge  dig  a  trench  12  inches 
deep  and  16  inches  broad.  In  this  lay  a  foundation  one  part  "ATLAS" 
Portland  Cement,  three  parts  clean,  coarse  sand  and  six  parts  broken  stone  or 
gravel.  On  the  foundations  and  at  equal  distance  from  either  edge  build  a 
solid  wall  (See  Walls)  8  inches  thick;  mixture,  one  part  "ATLAS"  Portland 
Cement,  two  parts  clean,  coarse  sand  and  four  parts  broken  stone,  gravel  or 
cinders. 


INTERIOR  OF  MUSHROOM  CELLAR  AT  WESTWOOD,  N.  J. 

Build  a  concrete  roof  3  inches  thick,  supported  by  concrete  beams  and 
posts  (see  Table,  Reinforced  Concrete  Beams  and  Slabs).  An  opening  should 
be  left  at  one  side  for  steps  (see  Steps).  All  walls,  posts,  beams  and  roof 
should  be  reinforced.  A  coat  of  grout,  one  part  "ATLAS"  Portland  Cement 
to  one  part  fine,  clean  sand  mixed  to  the  consistency  of  cream,  may  be  applied 
to  the  whole  exterior  with  a  brush  if  a  very  smooth  surface  is  required. 

129 


ARCH  DRIVEWAYS. 

Every  farm  or  house  along  a  country  road  must  have  one  or  more  bridges 
or  culverts  where  the  driveways  span  the  trench  or  ditch  alongside  the  road. 
These  arches  or  small  bridges  should  be  constructed  of  concrete,  for  then  they 
will  not  continually  rot  out  and  need  repairing  and  renewal. 

An  arch  driveway  consists  of  a  slab  supported  on  each  side  by  a  beam 
which  spans  the  ditch.  The  size  of  the  beams,  the  thickness  of  the  slab, 
and  the  amount  and  spacing  of  the  reinforcement  in  the  beams  and  slab  can 
be  taken  directly  from  the  table  on  page  30.  For  example,  take  an  arch 


ARCH  DRIVEWAY  NEAR  COLD  SPRINGS  HARBOR,  L.  I. 

driveway  of  1 2-foot  span,  having  an  8-foot  roadway.  The  heaviest  loading, 
namely,  125  pounds  per  square  foot,  will  be  taken  as  given  in  the  table. 
Beams  9  inches  wide  and  16  inches  deep,  reinforced  in  the  bottom  with  four 
9- 1 6-inch  rods,  are  required.  The  slab  must  be  3  inches  thick,  and  be  rein- 
forced with  5-1 6-inch  rods  placed  every  6  inches. 

The  arch  or  slab  should  be  constructed  during  a  dry  spell,  in  order  that 
little  or  no  water  need  be  taken  care  of  in  the  ditch.  The  forms  for  the  slab 
may  be  made  of  wood  if  desired,  or  it  can  be  constructed  as  follows:  If  the 

130 


ditch  is  not  entirely  dry,  place  a  closed  wood  trough  or  a  pipe  in  the  bottom  of 
the  ditch,  to  take  care  of  the  small  amount  of  water.  Throw  the  earth  which 
is  excavated  for  the  side  walls  into  the  ditch,  and,  if  necessary,  borrow  sand 
from  the  bank  beyond  to  bring  the  pile  of  sand  to  a  height  level  with  the 
bottom  of  the  new  arch  or  slab  to  be  built  and  wet  it  thoroughly.  Tamp  this 
fill  and  level  off  the  top  of  the  pile.  Place  some  boards  for  the  side  walls,  and 
brace  them.  Place  the  necessary  reinforcement,  upon  which  lay  the  concrete, 
composed  of  one  part  "ATLAS"  Portland  Cement,  with  two  parts  clean, 
coarse  sand  and  four  parts  screened  gravel  or  stone.  After  the  concrete  has 
set  for  a  week  or  two,  shovel  out  the  earth  from  under  the  arch,  and  the  drive- 
way is  ready  for  use. 


SPILLWAY  AT  DUMONT,  N.  J. 

CULVERT    DRIVEWAYS. 


Culvert  driveways  are  used  to  span  small,  shallow  runways  of  water. 

The  bore  or  opening  through  which  the  water  passes  is  generally  built 
circular,  although  a  square  or  rectangular  opening  may  be  used  as  well.  Line 
the  bottom  or  invert  of  the  opening  with  small  cobble  stones  or  gravel,  from 
which  the  sand  has  been  screened.  To  make  a  circular  bore  or  opening,  get 


131 


two  or  three  flour  barrels  or  cement  barrels,  with  the  heads  in,  place  them 
end  to  end  on  the  cobble  or  gravel  base  just  laid,  and  brace  them  in  position 
so  that  they  will  not  be  moved  when  placing  the  concrete.  If  desired,  a  layer 
of  concrete  can  first  be  laid  in  the  bottom  of  the  ditch,  on  which  the  barrels  can 
be  placed  and  braced.  After  placing  the  barrels  and  side  forms  in  position, 
lay  the  rest  of  the  concrete,  which  should  be  composed  of  one  part  "ATLAS" 
Portland  Cement  to  two  and  one-half  parts  clean,  coarse  sand  to  five  parts 
gravel  or  broken  stone.  The  walls  should  be  about  10  inches  thick  and  the 
top  of  the  arch  6  inches  thick.  To  remove  the  forms,  knock  in  the  heads  of 
the  barrels  and  pry  out  the  staves. 

WATER  PIPES  UNDER  DRIVEWAYS.  Concrete  water  pipes,  which  are 
covered  over  with  earth,  furnish  a  very  good  means  for  taking  care  of  water 
underneath  driveways.  The  pipes  are  constructed  in  the  same  manner  as  the 


STUCCO  CHICKEN  HOUSE  AT  ALLENTOWN,  PA. 

concrete  tile,  described  on  page  91,  and  may  be  made  up  to  12  or  16  inches 
in  diameter. 

HEN   NESTING   HOUSES. 

Hen  nesting  houses  constructed  of  concrete  are  better  and  if  a  number 
are  to  be  built  are  cheaper  than  if  constructed  of  any  other  material.  It  is 
impossible  to  keep  vermin  from  any  nesting  house,  and  consequently  the 

132 


nests  must  be  cleaned  artificially.  The  only  sure  way  to  clean  a  nest  is  by 
the  burning  out  process.  This  is  impossible,  of  course,  where  the  nests  are 
constructed  of  wood,  and  the  only  way  therefore  is  to  burn  them  every  so 
often  and  build  new  ones. 

It  is  hardly  necessary  to  state  the  advantages  of  a  concrete  nest,  but  a  few 
of  them  are:   (i)   that  it  is  cool  in  summer  and  warm  in  winter;   (2)   no 


ig-  37-  —  Design  for  Hen  Nesting  House. 


draughts  are  possible,  hence  the  hen  will  not  acquire  roup;  (3)  they  can  be 
burnt  out  after  each  nesting  so  as  to  destroy  all  germs,  leaving  the  nest  clean 
and  wholesome;  (4)  if  discolored  by  the  fire  the  nest  can  be  whitewashed 
after  each  firing. 

133 


A  good  size  for  a  hen  nesting  house  is  12  inches  wide,  15  inches  high  and 
1 8  inches  deep  inside  dimensions.  The  walls  and  back  should  be  2  inches 
thick,  while  the  front  is  left  entirely  open,  although  if  desired  a  lip  or  ledge 
can  be  cast  on  the  front  side.  The  ledge  can  be  made  out  of  wood  and  cut 
so  that  it  fits  snugly  in  the  concrete  and  this  can  be  removed  very  easily  when 
cleaning  the  nests.  The  forms,  as  shown  in  Fig.  37,  are  very  simple,  and  are 
made  so  that  a  number  of  nests  can  be  built  with  one  set  of  forms.  The 
outside  forms  consist  of  a  rectangular  box  without  any  ends  and  each  side 
made  as  a  separate  member  so  that  they  can  be  easily  taken  apart  after  the 
concrete  has  hardened.  When  nailing  the  sides  together  do  not  drive  the 
nails  home,  but  leave  the  heads  so  that  they  can  be  easily  drawn  with  a  claw 
hammer,  or,  better  still,  drive  the  nail  first  into  a  short  piece  of  lath  which 
can  be  easily  split  when  the  sides  of  the  form  are  to  be  removed,  and  thus  the 
heads  of  the  nails  will  stick  out  from  the  form  ^4  inch  and  can  be  easily  pulled 
out.  Nail  the  outside  form  together  with  the  two  bevel  pieces  for  the  top  of 
the  nest  tacked  in  and  place  on  either  hard  level  ground  or  a  plank  floor  or 
platform.  Oil  the  forms  well  so  that  they  can  be  easily  removed.  The  inside 
form  is  made  as  shown  in  the  figure,  having  a  hinge  at  the  peak  of  the  roof 
and  two  hinges  at  the  bottom  in  order  to  facilitate  removing  the  form.  It  is 
made  in  two  separate  sections  which  are  held  together  by  nailing  on  two  cleats 
to  serve  also  to  hold  them  in  the  outer  form  and  at  the  right  distance,  namely, 
2  inches  from  the  ground  or  platform.  After  placing  the  forms,  which  should 
be  well  greased,  mix  one  part  "ATLAS"  Portland  Cement  with  two  and  one- 
half  parts  of  clean,  coarse  sand  with  five  parts  of  screened  gravel  or  broken 
stone.  Place  the  layer  of  concrete  in  the  bottom  of  the  form  for  the  solid 
back  of  the  nest  and  then  fill  in  the  concrete  for  the  walls.  To  remove  the 
inside  form  take  off  the  two  top  cleats,  which  allow  the  two  slant  boards  to 
swing  together  on  the  hinge  at  the  top,  and  the  two  side  boards  swing  in  on 
to  the  base  boards,  making  it  possible  to  remove  them  very  readily. 

Thirteen  nests  can  be  made  from  one  barrel  (4  bags)  of  cement,  one-half 
of  a  single  load  (20  cubic  feet  per  single  load)  of  sand  and  one  load  of 
screened  gravel  or  broken  stone.  Figuring  cement  at  $2.00  a  barrel,  sand  at 
75  cents  a  cubic  yard  and  gravel  at  $1.25  per  cubic  yard,  the  cost  of  the 
material  for  the  concrete  for  each  nest  will  be  about  25  cents. 

CHICKEN    HOUSE. 

The  protection  afforded  by  a  concrete  chicken  house  against  rats,  weasels, 
and  other  vermin,  and  the  ease  with  which  such  a  structure  is  kept  clean, 
should  be  sufficient  reason  to  give  it  preference  over  every  other  kind. 

Excavate  a  trench  10  inches  wide,  to  a  depth  below  frost,  and  fill  with 
concrete  one  part  "ATLAS"  Portland  Cement,  three  parts  clean,  coarse  sand 

134 


CHICKEN  HOUSE  AT  WESTWOOD,  N.  J. 


CHICKEN  HOUSE  AT  MONTCLAIR,  N.  J. 
135 


and  six  parts  cinders.  On  this  foundation,  and  at  equal  distance  from  either 
edge,  build  a  solid  wall  5  inches  thick  (see  Walls),  one  part  "ATLAS" 
Portland  Cement,  two  and  one-half  parts  clean,  coarse  sand  and  five  parts 
clean  cinders  or  screened  gravel.  The  roof  may  be  made  of  wood  or  of 
concrete.  If  the  house  is  not  more  than  8  feet  wide,  a  roof  with  slope  in  one 
direction  may  be  made  of  a  4-inch  concrete  slab  reinforced  with  steel  rods  or 
heavy  wire  mesh  of  size  suggested  in  the  table  of  Reinforced  Beams  and  Slabs. 
For  a  shorter  span  a  less  thickness  may  be  adopted.  A  slope  of  six  inches  in 
eight  feet  will  give  sufficient  pitch  for  the  water  to  run  off  if  the  surface  is 
well  trowelled,  as  described  under  Sidewalks.  If  the  width  is  more  than  8 
feet,  concrete  rafters  may  be  placed  and  slabs  upon  them  of  dimensions  to  be 
selected  from  the  table  of  Reinforced  Beams  and  Slabs. 


CONCRETE  CHICKEN  HOUSE  AT  LAUREL  GROVE,  N.  J. 

Concrete  shelves  and  water  basins  can  be  put  in  to  suit  convenience. 

A  coat  of  mortar  one  part  "ATLAS"  Portland  Cement  and  one  part  fine 
clean  sand,  mixed  as  thick  as  cream,  may  be  applied  with  a  brush  to  the 
outside  walls  as  soon  as  forms  are  removed,  although  with  careful  placing 
of  the  concrete,  the  surface  may  be  wet  and  rubbed  down  as  soon  as  the  wall 
forms  are  removed  and  before  the  concrete  has  hardened,  with  a  board  or  a 
brick,  to  remove  the  board  marks  of  the  forms  and  leave  a  pleasing  rough 
surface. 

The  use  of  cinders  is  recommended  in  this  construction,  as  the  voids  in  the 
cinders  take  up  the  moisture,  which  is  otherwise  liable  to  collect  on  the  inside 
of  the  wall  in  cold  weather.  The  walls  may  be  made  with  a  hollow  space,  as 
shown  in  Fig.  31  (p.  102). 

136 


GREENHOUSES. 

A  greenhouse  built  of  concrete  not  only  does  not  require  constant  repairs, 
but  saves  fuel,  as  it  retains  heat  and  keeps  out  cold  air. 

Greenhouses  should  have  a  foundation  10  inches  broad  and  16  inches  deep, 
or  below  frost,  composed  of  mixture  one  part  "ATLAS"  Portland  Cement, 
three  parts  clean,  coarse  sand  and  six  parts  broken  stone.  On  this,  and  at 
equal  distance  from  either  edge,  erect  a  wall  7  inches  thick,  mixture  one  part 
"ATLAS"  Portland  Cement,  two  parts  clean,  coarse  sand  and  five  parts 


GREENHOUSE  AT  U.  S.  SOLDIERS'  HOME,  WASHINGTON,  D.  C. 

cinders,  to  the  height  required  for  the  walls.  A  ridgepole  can  be  erected,  6 
inches  wide  by  8  inches  deep,  of  concrete,  one  part  "ATLAS"  Portland 
Cement,  two  and  one-half  parts  clean,  coarse  sand  and  five  parts  broken  stone 
or  gravel  not  over  three-quarters  inch  in  size,  reinforced  with  two  steel  bars 
each  one-half  inch  in  diameter.  If  total  width  of  house  is  not  over  16  feet, 
beams  2^  inches  by  5  inches,  extending  from  ridgepole  to  side  wall, 
reinforced  with  a  %-inch  bar,  will  be  sufficiently  strong  to  support  the 
sashes. 

Reinforced  concrete  posts  8  inches  square  should  be  placed  at  intervals 
of  10  feet  to  support  the  ridgepole. 


CONCRETE  GREENHOUSE  WITH  CONCRETE  SASH  AT  WESTWOOD,  N.  J. 


INTERIOR  VIEW  OF  GREENHOUSE  AT  WESTWOOD,  N.  J. 
138 


GREENHOUSE  TABLES. 

The  tables  or  benches  in  greenhouses  should  be  constructed  of  concrete  in 
order  to  save  the  grower  the  large  expense  and  annoyance  of  renewing  and  re- 
placing every  few  years  the  old  decayed  wooden  benches.  The  tables  can  be 
made  either  as  one  member,  in  which  case  the  posts,  bottom  and  sides  are  cast 
in  one  continuous  piece  of  concrete,  or  they  can  be  made  by  constructing  them 
in  parts.  In  order  to  facilitate  the  drainage  of  the  water  from  the  table,  holes 


INTERIOR  VIEW  OF  GREENHOUSE  AT  GLEN  COVE,  L.  I. 

must  be  left  at  the  bottom  of  the  benches  except  when  the  bottom  is  cast  in  a 
series  of  slabs,  where  the  cracks  between  them  will  be  sufficient. 

Make  the  concrete  tables  which  are  cast  in  one  piece  2^/2  inches  thick  and 
of  a  mixture  composed  of  one  part  "ATLAS"  Portland  Cement  to  two  parts  of 
clean,  coarse  sand  to  four  parts  of  cinders,  reinforced  with  a  woven  wire 
fabric  or  %-inch  round  rods  spaced  7  inches  apart.  A  design  for  a  table  and 
forms  for  molding  the  separate  members  is  shown  in  Fig.  38.  The  posts 

139 


should  be  5  inches  square,  spaced  on  6-foot  centers,  and  the  table  may  be  made 
4  feet  wide.  If  the  slab  is  molded  in  sections,  as  shown  in  the  drawing 
(Fig.  38),  the  section  should  be  made  about  12  inches  in  width  for  convenience 
in  handling. 

The  forms  if  well  planned  and  greased  with  oil  should  leave  the  concrete 
surface  smooth  enough  without  plastering  them,  but  if  desired  a  coating  % 


6m. 


of  form  Removed 


J  in.  Boards 


/iinx/iin. 
Fig.  38.     Design  of  a  Separately  Molded  Greenhouse  Table. 

of  an  inch  thick,  of  one  part  "ATLAS"  Portland  Cement  to  one  part  of  clean, 
fine  sand,  may  be  applied  to  them.  This  should  be  put  on  after  the  surface  to 
be  covered  has  been  picked  with  a  stone  axe  or  old  hatchet  and  thoroughly  wet. 


140.' 


GREENHOUSE  AT  WESTWOOD,  N.  J. 


INTERIOR  OF  GREENHOUSE  AT  U.  S.  SOLDIERS'  HOME,  WASHINGTON,  D.  C. 

141 


CONCRETE    GREENHOUSE    TRAYS. 

Greenhouses  are  so  warm  that  the  moisture  is  soon  dried  out  from  the  air. 
To  supply  the  necessary  amount  of  moisture,  it  is  frequently  advisable  to 
keep  a  number  of  trays  filled  with  water  about  the  greenhouse.  The  larger 
the  surface  of  these,  the  greater  the  evaporation,  and  hence  the  better  pro- 
ducers of  moisture.  These  trays  are  most  satisfactory  if  constructed  of 
concrete,  because  the  concrete,  unlike  the  wood  ones,  do  not  rot,  and  do  not 
shrink  if  allowed  to  become  dry  and  consequently  need  little  attention  to  see 
that  they  are  always  filled.  The  concrete  trays  can  be  made  very  attractive, 
and  are  more  serviceable  than  if  made  of  any  other  material. 

Make  the  trays  like  the  slabs  for  tables  (see  page  140),  except  form  a  lip  all 
around  them  to  the  required  height.  Brush  a  layer  of  pure  "ATLAS"  Cement, 
mixed  to  the  consistency  of  thin  cream,  over  the  inner  surface  two  or  three 
hours  after  the  concrete  is  poured  to  make  them  water-tight.  Protect  from 
sun  and  keep  wet  until  they  are  to  be  used. 

Frequently  larger  tanks  are  preferred,  which  may  be  made  18  inches  wide 
by  1 8  inches  deep,  with  6-inch  reinforced  walls. 


CONCRETE  FLOWER  BOXES. 

CONCRETE  FLOWER  BOXES. 

Concrete  veranda  boxes  for  flowers  do  not  rot  and  therefore  do  not  have 
to  be  renewed  every  two  or  three  years.  They  are  attractive,  too.  not  only  on 
the  porch  of  any  stone,  stucco  or  cement  house,  but  are  ornamental  to  a 
frame  house. 

142 


The  length  of  the  concrete  veranda  box  is  generally  determined  by  the 
size  of  the  space  in  which  it  is  to  be  placed  on  the  veranda.  A  good  size  is 
5  feet  long,  8  inches  deep,  and  10  or  12  inches  wide.  The  outside  forms 
consist  of  a  long  rectangular  box,  which  may  have  the  two  long  sides  tapered 
if  desired,  so  that  the  box  will  be  10  inches  at  the  bottom  and  12  inches  at  the 
top.  This  will  make  the  finished  concrete  box  look  more  attractive  than  if 
made  with  perfectly  vertical  sides.  Use  planed  lumber  in  the  forms  and  oil 
them  thoroughly  on  all  the  surfaces  coming  in  contact  with  the  concrete. 
Line  the  outside  form  with  poultry  netting,  folding  it  at  the  end  or  corners 
so  as  to  make  a  reasonably  close  fit  to  the  walls  of  the  mold.  Place  the  inside 
form,  which  consists  of  a  bottomless  frame  having  dimensions  3  inches  smaller 
each  way  than  the  outside  one,  so  as  to  make  the  walls  i*/2  inches  thick.  Set 


CONCRETE  FLOWER  BOX  AT  PATERSON,  N.  J. 

this  inside  form  on  little  blocks  of  wood  to  keep  the  form  raised  1^2  inches 
from  the  bottom  of  the  outside  form.  These  wood  pieces  can  be  removed 
when  the  concrete  is  hard,  and  will  leave  holes  in  the  bottom  of  the  box  for 
draining  off  the  excess  water. 

Mix  a  batch  of  concrete  composed  of  one  part  "ATLAS"  Portland  Cement 
to  three  parts  clean,  gravelly  sand  which  has  been  screened  through  a  ^4-inch 
mesh  screen,  that  is,  a  screen  having  openings  J/£  inch  square.  Lay  the 
concrete,  which  should  be  of  the  consistency  of  mortar  for  laying  brick. 
Remove  the  inner  form  very  carefully  in  an  hour  or  two,  but  leave  the  outside 
form  at  least  until  the  next  day.  The  outside  surface  generally  need  not  be 
finished  off  further  than  wetting  it  down  thoroughly  and  rubbing  it  with  a 
wood  float  or  brick,  but  if  desired  it  may  be  finished  off  as  described  on  page  27. 
The  box  must  not  be  moved  for  at  least  a  week,  for  fear  of  cracking  it.  Wet 
it  occasionally  during  this  time. 

i43 


HOT-BED    FRAMES. 

Excavate  a  trench  to  a  depth  below  frost  and  erect  forms  for  a  4-inch  wall. 
Fill  with  concrete  mixture  one  part  "ATLAS"  Portland  Cement,  three  parts 
clean,  coarse  sand  and  six  parts  broken  stone  or  gravel,  to  level  of  the  ground. 
On  top  of  these  build  forms  for  a  3-inch  wall  to  height  desired,  and  fill  with 
concrete  of  the  same  proportions.  Remove  the  forms  in  two  or  three  days 
and  keep  the  walls  damp  for  a  couple  of  weeks. 


CONCRETE  COLD  FRAMES  AT  WESTCHESTER,  N.  Y. 


WINDMILL    FOUNDATION. 

The  great  danger  caused  by  the  rotting  of  wooden  windmill  foundations 
is  obviated  by  the  use  of  concrete. 

Excavate  four  holes  at  the  proper  distance  apart,  2^  feet  square  and  5 
feet  deep;  build  forms  for  the  sides  and  grease  properly.  Fill  forms  2  feet 
deep  with  concrete,  one  part  "ATLAS"  Portland  Cement,  three  parts  clean, 
coarse  sand,  six  parts  broken  stone  or  gravel,  of  a  jelly-like  consistency, 
tamping  well  every  six  inches.  To  insure  proper  location  of  holding-down 

144 


bolts,  construct  template  and 
hang  the  bolts  from  it,  as 
shown  in  Fig.  39,  and  fill  in 
concrete  around  them  until 
flush  with  top  of  form,  and 
allow  to  set  several  days  be- 
fore using.  This  gives  a  sub- 
stantial anchorage  for  a  steel 
tower. 

In  case  a  wooden  tower  is 
to  be  used,  run  projecting 
bolts  up  through  the  timber 
sills  and  use  large  cast-iron 
washers  under  the  nuts.  The 
anchorage  in  this  case  should 
project  at  least  6  inches  above 
the  ground. 


Fig.  39.     Form  for  Windmill 
Foundation. 


CONCRETE  WALK  AND  WINDMILL  FOUNDATION  AT  CLINTON,  IOWA. 

14.1 


CONCRETE  ROLLER. 

A  concrete  roller  may  be  made  as  a  hand  roller  to  be  operated  by  one  or 
two  men  or  as  a  horse  roller,  when  it  is,  of  course,  larger  and  heavier.  A 
hand  roller  for  two  men  suitable  for  rolling  lawns  should  be  made  about  18 
inches  in  diameter  and  24  inches  long.  This  size  of  roller  weighs  about  530 
pounds  or  265  pounds,  per  foot  of  length.  The  roller  shown  below  is  of 
the  dimensions  first  given  and  has  been  used  very  satisfactorily  for  several 
years. 


CONCRETE  ROLLER  AT  NEWTON,  MASS. 

A  form  for  making  a  concrete  roller  is  very  easily  and  cheaply  made,  as 
shown  in  Fig.  40.  For  a  roller  18  inches  in  diameter  and  24  inches  long  cut  a 
piece  of  sheet  iron  24  inches  by  25%  inches.  The  edges  must  be  cut  even  and 
must  be  square.  Make  two  sets  of  wood  clamps  like  the  circular  forms  shown 
on  page  20.  The  piece  of  sheet  iron  cut  to  the  dimensions  as  given  can  now 
be  bent  in  a  circle  and  nailed,  if  necessary,  to  the  two  wood  clamps.  Wire 
the  iron  form  or  jacket  with  No.  16  wire  to  hold  the  form  from  opening  at 
the  joint  when  the  concrete  is  placed.  Grease  or  oil  the  inside  of  the  form 
thoroughly  so  that  it  will  not  stick  to  the  concrete.  To  make  an  opening 
through  the  center  of  the  roller  for  an  axle  or  shaft,  place  a  %  or  %-inch  iron 
pipe  in  the  center  of  the  form.  The  axle  can  be  cast  in  the  roller  itself  if 
desired  instead  of  casting  a  %  or  %-inch  pipe  in  the  roller  in  which  to  place 
the  axle.  The  concrete  should  be  made  of  one  part  "ATLAS"  Portland 
Cement  to  two  parts  of  sand  to  four  parts  of  stone  or  gravel.  It  will  take  a 
little  less  than  one  bag  of  cement  for  a  roller  of  the  above  dimensions. 

146 


Sheet  /ron 
NP/6  W/re 


Fig.  40.     Form  for  Concrete  Roller. 


The  handle  for  a  hand  roller  may  be  made  of  %-inch  by  i-inch  iron,  bent 
and  welded  together  as  shown  in  the  figure.  Where  the  roller  is  heavier,  or 
is  to  be  operated  by  a  horse,  a  heavier  handle  and  different  design  of  handle 
can  be  easily  made. 

A  small  roller  for  rolling  seeded  ground  or  golf  greens  may  be  made  by 
pouring  concrete  into  a  piece  of  pipe  which  forms  the  outside  surface. 


DANCE  PAVILION  AT  TWIN  LAKE,  HARRISTOWN,  ILL. 

DANCE    PAVILION. 

The  photograph  of  the  pavilion  at  Twin  Lake,  Harristown,  111.,  shows 
what  can  be  accomplished  by  a  farmer  and  one  farm  hand  who  had  never 
before  had  any  experience  with  concrete.  There  are  16  posts  in  the  30  by 
40-foot  pavilion,  each  8  inches  by  n  inches,  and  the  walls  are  3  feet  high  and 
4  inches  thick.  The  lumber  used  for  the  forms  was  not  cut  up  any  more  than 
necessary  and  was  all  used  for  the  roof.  Thirty-five  barrels  of  "ATLAS" 
Portland  Cement  were  required  in  the  construction  of  the  posts,  walls  and 
floor.  Sand  and  gravel  found  on  the  farm  was  used  and  the  concrete  was 
proportioned  one  part  "ATLAS"  Portland  Cement  to  seven  parts  of  aggre- 
gates. A  3-inch  floor  was  laid,  using  the  same  mix  of  concrete,  and  was 
surfaced  with  a  ^4-inch  coat  of  mortar,  one  part  "ATLAS"  Portland  Cement 
to  one  part  of  sand. 

The  time  required  to  make,  place  and  remove  forms  was  two  days  each  for 
the  two  men.  It  took  them  10  days  to  mix  and  lay  the  concrete  for  the 
entire  structure. 

148 


PIAZZA. 

In  building  a  concrete  piazza  the  first  care  should  be  the  supports.  Unless 
these  are  strong  and  have  a  foundation  that  will  not  be  affected  by  frost,  the 
piazza  is  liable  to  prove  a  failure. 

Erect  two  lines  of  4-inch  posts,  8-inch  bases,  8  feet  apart,  extending  below 
frost.  The  outer  line  of  posts  should  be  slightly  lower  than  the  inner  line, 
which  is  next  to  the  house  to  allow  water  to  flow  off  the  piazza.  On  top  of 
and  connecting  these  in  both  directions,  build  concrete  cross  beams  and 
stringers  4  inches  by  8  inches.  Posts  should  be  reinforced  with  a  2/8-inch 


CONCRETE  PORCH  STEPS  AND  LATTICE  AT  WESTWOOD,  N.  J. 

steel  bar  and  beams  with  two  ^g-inch  bars  placed  one  inch  above  the  bottom. 
For  a  large  piazza,  refer  to  dimension  of  beams  and  reinforcement  in  Table 
for  "Designing  Reinforced  Concrete  Beams  and  Slabs,"  pages  30  and  31. 

After  the  concrete  has  set  hard,  erect  forms  and  build  a  solid  slab  of 
concrete  over  the  entire  framework,  allowing  it  to  project  slightly  over  the1 
outer  edge.  This  slab  should  be  reinforced  with  a  woven  wire  fabric  or 
expanded  metal  or  with  steel  rods,  using  the  size  and  spacing  given  for  slabs 
in  the  Beam  and  Slab  Table  just  mentioned. 

If  preferred  the  forms  for  the  beams  and  floor  may  be  built  at  the  same 
time,  and  the  concrete  poured  in  one  operation. 

149 


A  finished  surface  can  be  obtained  by  plastering  the  surface  one-half  inch 
thick  with  mortar,  one  part  "ATLAS"  Portland  Cement  and  one  part  clean, 
coarse  sand,  before  the  concrete  has  set  and  trowelling  it  hard  as  the  mortar 
begins  to  stiffen. 

LATTICE. 

In  building  a  lattice,  the  fact  that  there  are  two  thicknesses  of  concrete, 
i.  e.,  the  thickness  of  the  panel  or  border  and  the  thickness  of  the  lattice  itself, 
should  be  borne  in  mind. 

Build  a  form  8  inches  higher  and  8  inches  longer  than  the  size  the  finished 
lattice  is  to  be,  using  2-inch  stuff.  Along  the  top,  bottom  and  at  either  end, 
nail  a  4-inch  by  4-inch  scantling,  and  on  these  nail  a  2-inch  by  8-inch  plank 


B- 


— B 


Elevation  ofLcrff/ce  w/fh  parf  of  form  removed . 


Secffon  /?.  ft 


Section  B.&. 
Fig.  41.    Forms  for  Concrete  Lattice. 

(see  Fig.  41).  On  the  back  of  the  form,  at  equal  distances  apart  and  equal 
distances  from  the  edge  of  the  2-inch  by  8-inch  plank,  nail  securely  blocks  of 
wood  of  the  shape  of  the  holes  desired.  (See  holes  in  lattice  in  accompanying 
cut.)  Lay  the  form  thus  made  on  the  ground,  face  up,  and  block  securely. 
Fill  with  concrete  one  part  "ATLAS"  Portland  Cement,  two  parts  sand  and 
four  parts  fine  broken  stone  or  gravel  to  the  level  of  small  blocks  for  holes, 
and  pack  concrete  all  around  under  the  2-inch  by  8-inch  plank  to  form  panel ; 
tamp  hard,  making  sure  there  are  no  voids.  Smooth  off  face  of  concrete 
and  let  stand  for  a  week,  or  until  the  concrete  is  thoroughly  dry.  If  the 
surface  is  not  smooth  enough  a  coating  of  grout,  one  part  "ATLAS"  Portland 
Cement  and  one  part  fine,  clean  sand,  mixed  as  thick  as  cream,  may  be  applied 
with  a  brush  after  first  roughening  surface  and  wetting  it  thoroughly.  A 
moderately  dry  concrete  should  be  used  in  this  form. 

150 


The  lattice  may  be  built  in  place  by  leaving  off  the  4  inches  by  4  inches 
at  the  top  of  form  and  boarding  up  the  open  space  in  front  of  "hole-blocks" 
with  a  i  ^2-inch  plank  and  pouring  the  concrete  in  from  the  top  (Fig.  41).  A 
very  wet  concrete  should  be  used  if  this  plan  is  followed. 

CHIMNEY   CAPS. 

Chimney  caps  of  concrete  are  rapidly  supplanting  stone,  brick  or  iron,  as 
they  are  not  only  cheaper  and  more  durable,  but  protect  the  top  of  chimney 
better. 


Fig.  42.     Forms  for  Chimney  Cap. 


CHIMNEY  CAP  AT  CHESTNUT  HILL,  MASS. 


Make  a  bottomless  box  the  size  of  the  re- 
quired cap,  and  one  or  more  small  bottom- 
less boxes  to  correspond  to  the  flue  or  flues 
of  the  chimney,  and  y*  inch  higher,  so  that 
the  surface  of  the  concrete  can  be  sloped  to 
allow  water  to  flow  off,  and  set  in  place  (Fig. 
42).  The  thickness  is  usually  about  4  inches, 
but  this  can  be  varied  to  suit  convenience. 
Plaster  the  inside  surface  of  the  large  mold 
with  2  inch  of  stiff  mortar  and  then  imme- 


diately  fill  form  one-half  full  with  one  part  "ATLAS"  Portland  Cement,  three 
parts  clean,  coarse  sand  and  six  parts  broken  stone,  and  put  in  reinforcing, 
either  woven  wire,  expanded  metal  or  %-inch  rods,  complete,  and  tamp  until 
water  puddles  on  top.  When  partly  set,  trowel  smooth. 

If  it  is  desired  to  build  the  cap  in  place,  the  following  plan  should  be 
adhered  to :  Place  small  rods  across  the  chimney  between  the  flues.  On  these 
build  platform  of  tongue  and  grooved  board  planed  on  upper  side  and  driven 
snug  together,  but  not  nailed.  On  this  platform  place  the  forms  previously 
described  and  fill  with  reinforced  concrete.  After  the  concrete  has  set  (at 
least  a  week  is  needed)  remove  platform  and  rods  by  raising  each  side  of 
chimney  cap  alternately  and  knocking  platform  apart.  Remove  outer  and 
inner  forms.  Raise  one  end  of  slab,  cover  all  accessible  surface  of  top  of 
chimney  with  mortar,  lower  cap  on  bed  thus  formed  and  remove  rods  under 
end.  Repeat  process  at  opposite  end. 


REMOVING  DECAYED  MATTER  FROM  TREE 
BEFORE  FILLING 

TREE 


TREE  WITH  CAVITY  FILLED  WITH 
CONCRETE 


SURGERY. 

Tree   surgery  not   only  consists   in   cutting   away   all   the   decaying   and 
dead  matter  of  the  tree,  but  embraces  also  the  pruning  and  chaining  of  limbs, 

152 


scraping,  and  filling  of  cavities.  Through  the  skillful  methods  used  by  the 
tree  surgeon  it  is  possible  to  give  a  new  lease  of  life  to  trees  which  apparently 
have  reached  their  limit  of  existence.  The  cavities  are  caused  by  poor 
pruning  of  limbs,  the  breaking  off  of  branches  and  other  injuries.  While  the 
treatment  of  the  cavities  varies  more  or  less  in  different  cases,  if  the  specifica- 
tions given  below  are  followed  closely  a  good  job  should  result. 

The  tree  ;grows  in  girth  by  the  deposit  of  a  thin  layer  of  new  wood 
between  the  wood  and  the  bark.  It  is  this  new  layer  and  others  recently 
formed  which  are  known  as  the  sapwood  and  form  the  active  section  of  the 
trunk  and  branches.  The  inner  rings  are  gradually  covered  by  the  yearly 
deposit  of  this  new  growth,  and  in  turn  the  living  sapwood  becomes  heart- 
wood,  which  is  dead,  and  serves  merely  as  a  strong  framework  for  the  living 
parts  of  the  tree.  This  is  the  reason  why  hollow  trees  may  often  be  found  in  a 
flourishing  condition  when  the  heartwood  has  entirely  disappeared. 
FILLING  THE  CAVITY.  Cut  out  all  the  deceased  and  decaying  part  of 
the  tree  without  regard  to  the  size  of  the  wound  which  is  made.  This  must 
be  cleaned  out  with  the  same  thoroughness  which  a  dentist  uses  when  cleaning 
the  cavity  of  a  tooth  for  a  filling.  If  all  of  the  decayed  matter  is  not  removed 
the  decay  will  continue  as  if  the  filling  had  not  been  placed.  Disinfect  the 
freshly  cut  surfaces  with  a  coat  of  creosote  or  crude  petroleum  oil.  Heat  some 
coal  tar  and  apply  a  thick  coat  to  the  disinfected  surfaces.  This  coat  of  tar 
applied  thick  serves  as  a  plastic  substance  to  prevent  any  cracks  between  the 
cement  and  the  wood  from  shrinkage.* 

The  cavity,  if  it  is  a  large  one,  may  be  reinforced  to  better  hold  the 
concrete  in  place  with  either  some  woven  wire  mesh  reinforcement  or  with 
small  steel  rods  placed  across  from  side  to  side  of  the  cavity.  Cut  back  the 
bark  for  about  %  of  an  inch  or  so  around  the  entire  wound  in  order  to  prevent 
bruising  it  while  the  work  is  in  progress,  and  in  order  to  get  the  cement 
perfectly  flush  with  the  wood,  which  cannot  be  done  when  the  bark  is  not 
cut  away. 

For  a  large  cavity  some  kind  of  a  form  must  be  used  to  prevent  the 
concrete  from  caving  out  when  it  is  being  placed.  For  this  boards  may  be 
fitted  to  the  opening,  leaving  a  space  at  the  top  to  pour  in  the  concrete;  or 
metal,  like  zinc  or  tin,  may  be  thoroughly  greased  and  tacked  on.  When  it 
is  ready  mix  up  a  batch  of  concrete  composed  of  one  part  "ATLAS"  Portland 
Cement,  two  parts  of  sand  and  four  parts  of  screened  gravel  or  stone  made  up 
to  a  rather  stiff  consistency,  about  like  jelly. 

If  the  opening  to  the  cavity  is  small,  so  that  no  form  is  required,  trowel 
the  surface  of  the  concrete  lightly  so  as  to  leave  it  smooth.  If  the  concrete 
is  too  soft  to  make  a  good  vertical  surface  or  if  the  upper  part  of  the  cavity  is 


*Methods  similar  to  these  have  been  used  by  Mr.  G.  E.  Stone,  of  the  Massachusetts 
Agricultural  College,  for  a  number   of  years. 

153 


not  entirely  filled,  wait  for  two  or  three  hours  until  the  concrete  has  begun 
to  stiffen,  ram  it  in  again  to  completely  fill  the  hole  and  then  trowel  the 
surface,  adding  a  little  stiff  concrete  if  necessary. 

If  forms  are  used,  remove  them  as  soon  as  possible,  either  in  a  few  hours 
or  else  the  next  day,  and  go  over  the  surface  so  as  to  slightly  roughen  it  and 
remove  the  form  marks. 

The  bark  on  a  tree  treated  in  this  way  will  in  time  grow  over  the  concrete 
and  in  some  cases  not  even  leave  a  scar. 

CONCRETE    AQUARIUM. 

Aquariums  constructed  of  concrete  can  be  made  attractive  and  have  been 
found  very  serviceable.  At  the  fisheries  at  Cold  Springs  Harbor,  L.  I., 
some  of  these  concrete  aquariums  have  been  in  service  since  1904  and  look 
as  good  to-day  as  when  first  made. 

Make  the  base  or  bottom  of  each  tank  18  by  31  inches  and  the  vertical  sides 
J3  by  15  inches,  all  being  2  inches  thick.  Make  the  sides  with  vertical  grooves 


THIRTY-FOOT  DIAMETER  CONCRETE  FOUNTAIN  AT  UNION,  PA. 
(1:4  Mix,  6-inch  Thick  Walls,  10  inches  Deep) 

i  J4  inches  from  the  edge  in  order  to  set  in  the  glass  sides.  Leave  grooves  in 
the  bottom  also  so  that  the  glass  sides  can  be  puttied  in  and  be  made  water- 
tight at  the  joints. 

CONCRETE    BLOCKS. 

During  the  past  few  years  concrete  blocks  have  been  used  extensively  and 
many    patents    have    been    granted    the    manufacturers    of    concrete    block 


DETAIL  OF  CONCRETE  PEBBLE-FINISHED  RESIDENCE  AT  WESTWOOD,  N.  J. 


STUCCO  COTTAGE  AT  CEDARHURST,  L.  I. 
155 


machines  for  the  various  devices  and  methods  employed.  Buildings  con- 
structed with  concrete  blocks  have  proved  satisfactory  when  the  blocks  have 
been  made  with  care  and  with  proper  materials. 

STUCCO. 

Stucco  work  is  cement  plastering,  and,  in  one  form  or  another,  has  been 
in  use  for  ages.  It  is  durable,  artistic  and  impervious  to  weather.  For 
veneering  new  buildings,  or  protecting  old  structures,  and  wherever  the  cost 
of  solid  concrete  is  prohibitive,  Portland  Cement  Stucco  cannot  be  equaled. 

Stucco  work  may  be  used  to  cover  wood,  brick,  stone  or  any  other  building 
material,  provided  special  precautions  are  taken  in  preparing  the  surface 
properly  so  that  it  will  adhere  and  not  crack  or  scale  off.  The  work  should 
be  done  by  an  experienced  plasterer. 

As  a  rule  two  coats  are  used — the  first,  a  scratch  coat  composed  of  five 
parts  "ATLAS"  Portland  Cement,  twelve  parts  clean,  coarse  sand  and  three 
parts  slaked  lime  putty  and  a  small  quantity  of  hair;  the  second,  a  finishing 
coat  composed  of  one  part  "ATLAS"  Portland  Cement,  three  or  even  five 
parts  clean,  coarse  sand  and  one  part  slaked  lime  paste.  Should  only  one 
coat  be  desired  the  finishing  coat  is  used.  Some  masons  prefer  a  mortar  in 
which  no  lime  is  used,  but  this  requires  more  time  to  apply  it. 

To  apply  Stucco  to  brick  or  stone  or  concrete,  clean  the  surface  of  the 
wall  thoroughly,  using  plenty  of  clean  water  so  as  to  soak  the  wall.  If 
the  surface  is  concrete  roughen  it  by  picking  with  a  stone  axe.  Plaster  with  a 
1 5/2-inch  coat  and  finish  the  surface  with  a  wood  float,  or  to  make  a  rough 
surface  cover  the  float  with  burlap.  Protect  the  stucco  work  from  the  sun 
and  keep  it  thoroughly  wet  for  three  or  four  days;  the  longer  it  is  kept  wet 
the  better. 

In  using  Stucco  on  a  frame  structure,  first  cover  surface  with  two  thick- 
nesses of  roofing  paper.  Next  put  on  furring  strips  about  one  foot  apart,  arid 
on  these  fasten  wire  lathing.  (There  are  several  kinds,  any  of  which  are 
good.)  Apply  the  scratch  coat  J/£  inch  thick  and  press  it  partly  through  the 
openings  in  the  lath,  roughing  the  surface  with  a  stick  or  trowel.  Allow  this 
to  set  well  and  apply  the  finishing  coat  */2  inch  to  i  inch  thick.  This  coat  can 
be  put  on  and  smoothed  with  a  wooden  float,  or  it  can  be  thrown  on  with  a 
trowel  or  large  stiff-fibered  brush,  if  a  spatter-dash  finish  is  desired.  A 
pebble-dash  finish  may  be  obtained  with  a  final  coat  of  one  part  "ATLAS" 
Portland  Cement,  three  parts  coarse  sand  and  pebbles  not  over  *4  mch  m 
diameter,  thrown  on  with  a  trowel. 

COLORING    FOR    CONCRETE    FINISH. 

The  use  of  colored  concrete  up  to  the  present  time  has  not  been  general, 
and  the  effect  of  coloring  ingredients  upon  the  strength  of  concrete  is  not 
definitely  known. 

156 


METHOD  OF  APPLYING  PEBBLE  DASH  FINISH 
157 


In  his  book  on  "Cement  and  Concrete,"*  Mr.  L.  C.  Sabin,  an  eminent 
authority,  states  that  the  dry  mineral  colors  mixed  with  the  water  in 
proportions  by  weight  of  from  two  to  ten  per  cent,  of  the  cement  give  shades 
approaching  the  color  used,  with  no  apparent  effect  on  the  early  hardening 
of  the  mortar. 

Mr.  Sabin  also  gives  the  following  table,  showing  the  result  obtained 
from  a  dry  mortar  (wet  mortars  give  a  darker  shade)  : 

COLORED  MORTARS 
Colors  Given  to  Portland  Cement  Mortars  Containing  2  Parts  River  Sand  to  1  Cement. 


Dry 

Material 
Used 

WEIGHT  OF  DRY  COLORING  MATTER  TO  100  POUNDS  OF 
CEMENT 

Cost  of 
Coloring 
Matter  per 
Pound,  Ct. 

Y^  Pound 

1  Pound 

2  Pounds 

4  Pounds 

Lamp  Black 

Light  Slate 

Light  Gray 

Blue  Gray 

Dark  Blue 

Slate 

15 

Prussian  Blue 

Light  Green 
Slate 

Light  Blue 
Slate 

Blue  Slate 

Bright  Blue 
Slate 

50 

Ultra  Marine 
Blue 

Light  Blue 
Slate 

Blue  Slate 

Bright  Blue 
Slate 

20 

Yellow  Ochre 

Light  Green 

l     Light  Buff 

3 

Burnt  Umber 

Light  Pinkish 
Slate 

Pinkish  Slate 

Dull  Lavender 
Pink 

Chocolate 

10 

Venetian  Red 

Slate,  Pink 
Tinge 

Bright  Pink- 
ish Slate 

Light  Dull 
Pink 

Dull  Pink 

2y2 

Chattanooga 
Iron  Ore 

Light  Pinkish 
Slate 

Dull  Pink          Light  Terra 
Cotta 

Dull  Brick 
Red 

2 

Red  Iron  Ore 

Pinkish  Slate 

Dull  Pink 

Terra  Cotta 

Light  Brick 
Red 

11A 

'Cement  and  Concrete,"  Louis  Carlton  Sabin;     McGraw  Publishing  Company,  N.   Y. 


BURNT  BARN  AT  BROOKSIDE  FARM  SHOWING  CONCRETE  BUILDING  IN  REAR  IN  WHICH  THE  LEAD 
TRAPS  ON  THE  SINKS  WERE  NOT  EVEN  MELTED  OFF 

158 


CULVERTS.* 

Concrete  culverts  of  all  sizes  and  shapes  are  being  constructed  not  only 
where  the  roads  have  been  fully  developed,  but  also  on  a  great  many  farm 
roads.  They  are  cheaper  than  wooden  culverts  considering  that  the  wooden 
ones  rot  out  every  few  years.  If  desired,  they  can  be  made  quite  artistic. 

Culverts  vary  greatly  in  size,  from  those  which  are  nothing  more  than  a 
large  sewer  pipe  to  those  which  span  a  wide  stream. 


im 


CULVERT  AT  HARRISTOWN,  ILL. 

The  bore  or  opening  through  which  the  water  passes  may  be  made  either 
circular  or  rectangular.  Culverts  are  generally  built  with  a  circular  bore, 
although  the  forms  for  these  are  more  difficult  to  make  than  for  the  rectangu- 
lar, so  that  frequently  the  latter  are  much  cheaper. 

A  culvert  should  be  built,  if  possible,  during  the  dry  season  or  when  the 
water  is  low.  When  of  such  size  as  to  make  it  impracticable  to  build  it 
by  having  the  water  flow  through  the  center  in  a  trough  or  flume,  then  build 
a  dam  above  the  culvert  and  convey  the  water  around  one  side  of  the  proposed 
new  structure  while  the  work  is  in  progress  by  means  of  a  wooden  trough  or 
a  deep  ditch. 


*For  further  detail  information  see  "Concrete  in  Highway  Construction,"  published 
by  The  "ATLAS"  Portland  Cement  Co. 

159 


_ 

/ 

t-     /o^x1     —  * 

<0 

! 

^k 

—  f^  \ 

<0 

•i 

?dr-             // 

iact 

£'F?oc(<s  bent       I 

Earth  f//kng 

•      — ^ 


ongifud/na/  Secf/on 


e//o/ 


' 


1 1 


Efe.vaf/o/7 


P/on 

Fig.  43.    Design  for  a  5-Foot  Arch  Culvert. 


£/?c/  Elevation 
All  Rods 


vS/c/e  E/Bvaf/on  P/an 

Fig.  44.    Design  for  an  8-Foot  Arch  Culvert. 
1 60 


CULVERT  AT  DES  MOINES,  IOWA. 


CULVERT  AT  MORTON,  ILL. 
Z6l 


The  footings  of  the  culvert  can  usually  be  laid  directly  on  the  earth  in 
the  bottom  of  the  trench  dug  for  them.  Where  the  ground  is  soft,  place  wide 
footings  under  the  culvert,  and  if  deep  marsh  is  encountered  excavate  to  hard 
soil  and  fill  with  gravel  well  rammed  or  else  drive  piles  to  prevent  the 
settlement. 

In  a  small  culvert  set  the  forms  complete  and  place  the  concrete  for  the 
whole  culvert  in  one  operation.  In  a  large  culvert  this  is  not  practicable,  in 
which  case  set  rough  forms  for  the  footings  and  up  to  the  springing  line  of  the 
arch.  After  laying  the  concrete  to  this  level  set  up  the  arch  centers  and 
wing  wall  forms.  Oil  the  forms  well.  The  wing  wall  forms  may  be  built 
of  i -inch  boards  laid  horizontally  against  2  x  4-inch  studs.  The  inner  wing 
wall  form  must  be  cut  somewhat  to  the  shape  of  the  arch  or  stepped  off 
around  the  arch.  The  top  of  the  arch  needs  forms  from  the  springing  line  up 
to  about  one-half  to  three-quarters  of  the  way  to  the  crown,  as  the  wet 
concrete  will  not  stand  on  so  steep  a  slope. 

The  mix  of  concrete  for  culverts  should  be  one  part  "ATLAS"  Portland 
Cement  to  two  and  one-half  parts  of  clean,  coarse  sand  to  five  parts  of 
screened  gravel  or  broken  stone.  The  amount  of  materials  for  the  culverts 
given  in  Figs.  43,  44  and  45,  is  tabulated  in  the  table  below.  If  the  excavation 
must  be  deeper  than  shown,  of  course  more  material  will  be  needed. 


AMOUNT  OF  MATERIALS  FOR  ARCH  CULVERTS. 


MATERIALS   FOR  CULVERT  FOR   10-FT.   ROADWAY 
(See  Fig.  46) 


Screened* 

Screened 

Span  of 

Sand* 

Gravel  or 

Sand 

Gravel  or 

Culvert 

Cement 

Double 

Stone 

Cement 

Double 

Stone* 

Load 

Double 

Load* 

Double 

Feet 

Bags  Bbls. 

Load 

Bags  Bbls. 

Load 

5 

50  or  \2y2 

3 

6 

2  or  y2 

/'s 

y* 

8 

80  or  20 

4^ 

9# 

3  or  *4 

n 

H 

10 

115  or  283^ 

7 

14 

4  or  1 

X 

K 

EXTRA     MATERIAL     FOR    EACH     ADDI- 
TIONAL FT.   WIDTH  OF  ROAD 


*A  double  load  of  sand  or  gravel  is  taken  as  40  cubic  feet  or  about  1 J^  cubic  yards. 

Fig.  46  shows  a  form  for  an  arch  culvert  and  also  the  flume  box  in  place) 
to  take  care  of  the  water  during  construction.  The  inside  wall  form  is 
constructed  in  the  same  manner  as  the  wall  forms  previously  explained, 
except  that  a  3  by  4-inch  or  a  4  by  4-inch  ranger  is  set  across  the  top  of  the 
cleats  on  which  the  wedges  are  placed  to  support  the  arch  form.  The  wedges 
should  separate  the  two  forms  at  least  3  inches  so  that  when  the  forms  are 

162 


I 

o 


M> 


163 


to  be  removed  the  arch  center  can  drop  this  distance  and  be  readily  removed. 
A  strip  of  sheet  iron  should  be  nailed  to  the  side  forms  as  shown  and  lap  over 
on  to  the  arch  form  to  prevent  the  concrete  from  getting  in  between  the  forms, 
in  which  case  it  would  be  impossible  to  remove  the  arch  form  without 
breaking  it  to  pieces.  After  pulling  out  the  arch  form  the  side  forms  can  be 
easily  removed.  The  circular  forms  or  braces  which  support  the  i^-inch 
lagging  should  be  placed  on  4-foot  centers,  or  if  i-inch  lagging  is  used  space 
the  forms  2  feet  apart. 

Fig.  47  is  the  standard  type  of  form  and  culvert  used  by  the  Iowa  State 
Highway  Commission.  The  invert  or  water  table  in  this  case  is  shown  as  a 
concrete  slab,  but  this  may  be  omitted  in  some  cases  and  can  be  used  if  desired 
in  an  arch  culvert  as  well.  Where  an  invert  or  bottom  of  concrete  is  used  it 
must  be  protected  at  both  ends  by  an  apron,  as  shown  in  the  figure,  to  prevent 
the  water  from  washing  the  earth  from  underneath  it. 


<t? 

CM 


of  Fto  ad 


£~crr/Jf?  ft/hn^jj$. 


of  /ess  than 
I 2.  in 


~nd  E/evat/on 

-/pin. 

/a  in 


LoncjiTudinal   v5ec//o/7 


vS/c/e 


Plan 
Fig.  45.    Design  for  a  lO-Foot  Arch  Culvert. 


A  good  method  of  making  the  invert  of  a  culvert  is  to  lay  cobble  or  field 
stones  as  shown  in  the  figures.  This  can  be  done  even  when  there  is  consider- 
able water  running  through  the  culvert,  and  should  a  dry  spell  occur  the 
cobbles  can  be  plastered  or  grouted  over,  making  a  very  satisfactory  and 
efficient  invert. 


164 


/lx-4//?.  Lagging 


Fig.  46.    Design  of  Forms  for  Arch  Culvert. 


CONCRETE  COAL  CHUTE,  DUMONT,  N.  J. 
165 


CONCRETE  CISTERN  COVER,  HA.RRISTOWN,  ILL. 


-** 


FRUIT  CELLAR  AT  WESTWOOD,  N.  J. 
1 66 


DOG  HOUSE  AT  WEST  WOOD,  N.  J. 


ENGINE  BASE  IN  WELL  HOUSE  AT  COLUMBIA,  MO. 
I67 


CONCRETE  FLUME.  REDLANDS,  CALIFORNIA 


CONCRETE  BLOCK  FIREPLACE  AT  CEDAR  BROOK,  N.  J. 
168 


CONCRETE  IN 

HIGHWAY 
CONSTRUCTION 


A  Text-Book  for   Highway 
Engineers  and  Supervisors 


Price  $1.00 


Published    by 

THE   ATLAS    PORTLAND   CEMENT   CO. 

30    Broad    Street 

NEW   YORK 


Copyright  1909 

by 

THE  ATLAS  PORTLAND  CEMENT  Co. 
30  Broad  Street,  N.  Y. 

All  rights  reserved 


INDEX. 

PAGE 

Foreword    9 

CHAPTER  I. — CONCRETE. 

Cement    13 

Storing  Cement 14 

Sand  or  Fine  Aggregate 14 

Coarse  Aggregate 15 

Water   16 

Proportions  of  Materials 16 

Quantities  of  Materials  in  Concrete 18 

Table  of  Volume  of  Concrete  Made  from  One  Barrel  of  Portland  Cement.  .  18 

Table  of  Quantities  of  Material  per  Cubic  Yard  of  Rammed  Concrete 19 

Table   of   Volume  of   Plastic   Mortar   Made   from  Different   Proportions  of 

Cement  and  Sand 20 

Rubble    Concrete 20 

Mixing  Concrete 20 

Hand    Mixing 21 

Placing    Concrete 23 

Laying  Concrete  in  Water 23 

Laying  Concrete  in  Sea  Water 24 

Effect  of  .Manure 24 

Freezing   24 

Forms   25 

CHAPTER  II. — SIDEWALKS,  CURBS  AND  GUTTERS. 

Dimensions  of  Walks,  Curbs  and  Gutters 27 

Foundations  and  Drainage 28 

Proportions  for  Concrete 30 

Forms 30 

Placing   Concrete 31 

Coloring   Matter 35 

Table  of  Materials  for  Concrete  Sidewalks,  Floors  and  Walls 35 

Quantities   of   Material 36 

Cost 36 

Vault  Light  Construction 38 

CHAPTER  III. — STREET  PAVEMENTS. 

Concrete  Street  Pavement  Foundations 41 

Proportions  of  Concrete  for  Street  Foundations 42 


PAGE 

Cost  of  Concrete  Foundations  in  Place 42 

Mixing  of  Concrete 43 

Gang  for  Hand-Mixed  Concrete 43 

Construction  of  Foundations 44 

Crowning  of   Roadways 44 

Table  of  Offsets  for  Crowning  Streets  of  Various  Widths 45 

Foundations  Under  Street  Railway  Tracks 46 

Concrete    Pavements    46 

Essentials  of  a  Concrete  Pavement 47 

Blome  Company  Granitoid  Concrete  Pavement 48 

General  Specifications  for  the  Blome  Company  Granitoid  Concrete  Blocked 

Pavement 49 

Preparation  of   Sub-Grade 49 

Foundation    , 49 

Materials    49 

Sand    49 

Crushed    Stone 50 

Gravel    50 

Mixing  and  Laying  of  Concrete  and  Formation  of  the  Blome  Company  Grani- 
toid   Blocking    50 

Surfacing    Material 50 

Expansion    Joints 51 

Patents    51 

Guaranty     51 

Bidders'  Attention 51 

Cost  of  Blome  Company  Granitoid  Pavement 52 

Hassam   Pavement 53 

Hassam  Grouted  Concrete  Pavement 53 

Long  Island  Motor  Parkway 54 

Cost  of  Hassam  Pavement 56 

Hassam  Granite  Block  Pavement .  .  .  56 

Concrete  Pavement  in  Richmond,  Ind 57 

Concrete  Pavements  in  the  City  of  Panama 58 

Grouting  Stone  Block  and  Brick  Pavements 59 

CHAPTER  IV.— SEWERS,  DRAIN  TILES,  BROOK   LININGS  AND  CONDUITS. 

Sewers    50 

Concrete  Pipe  Sewers 61 

Table  of  Tests  of  Plain  Concrete  Sewer  Pipe  in  Brooklyn 61 


PAGE 

Large   Concrete   Sewers 63 

Table  of  Thickness  of  Conduits 63 

Sizes  of  Circular  Concrete  Sewer  Pipe 63 

Proportions  of  Concrete  for  Sewer  Pipe 64 

Concrete   Drain   Tile 65 

Size  of  Concrete  Drain  Tiles 65 

Mixtures  for  Tiles 65 

Curing    65 

Laying  Drain  Tiles 66 

Brook    Linings 67 

Conduits   69 

CHAPTER  V. — CULVERTS. 

Box  Culverts  73 

Circular  or  Pipe  Culverts 78 

Arch  Culverts 79 

Table  of  Quantity  of  Materials  for  Arch  Culverts 84 

Preparing    the    Bed 84 

Forms  for  Arch  Culverts 85 

CHAPTER  VI. — BEAM  BRIDGES. 

Kinds  of  Concrete  Bridges 88 

Types  of  Flat  Bridges 88 

Proportions  for  Concrete 89 

Steel    Reinforcement 89 

Slab   Bridges 89 

Table  of  Principal  Dimensions  and  Quantities  of  Materials  for  Slab  Bridges.  91 

Combination  Beam  and  Slab  Bridges 93 

Method  of  Construction  of  Combined  Beam  and  Slab  Bridges 97 

Girder   Bridges 97 

Concrete  Floors  for  Steel  Bridges 99 

Cost  of  Beam  and  Slab  Bridges 100 

CHAPTER  VII. — ARCH  BRIDGES. 

Plain  and  Reinforced  Concrete  Arches 102 

History  of  Concrete  Arches 103 

Types  of  Concrete  Arches 103 

Preparation    of    Plans 104 

Design  for  Forty-Foot  Span 105 


PAGE 

Expansion   Joints . . 107 

Reinforced  Concrete  Arch,  Elm  Street,  Concord,  Mass. 107 

Falsework  and  Centering Ill 

Placing    Concrete Ill 

Earth    Filling 114 

Striking    Centers 114 

Surface    Finishing 114 

Cost    115 

CHAPTER  VII. — RETAINING  WALLS. 

Kinds  of  Retaining  Walls 118 

Gravity   Retaining   Walls 120 

Copings    121 

Forms   for  Gravity   Walls 122 

Dimensions  of  Gravity  Walls 123 

Table  of  Dimensions  and  Quantities  of  Gravity  Retaining  Walls 123 

Reinforced   Retaining  Walls 124 

Proportions  of  Concrete 126 

Expansion   Joints 127 

Drainage    127 

CHAPTER  IX. — MISCELLANEOUS. 

Fence    Posts 128 

Concrete  Fence  Posts  at  Dellwood  Park 130 

Hitching   Posts 131 

Lamp    Posts 132 

Drinking  Fountains 133 


FOREWORD. 

The  development  of  manufacture  and  of  agriculture,  which  require  proper 
transportation  facilities  not  only  on  the  railroads  but  to  the  points  of  ship- 
ment and  distribution,  has  stimulated  a  widespread  interest  and  called  national 
attention  to  the  necessity  for  better  pavements  and  for  highway  constructions 
of  a  more  permanent  and  durable  character. 

This  demand,  as  well  as  the  necessity  for  reducing  the  expense  of  repairs 
incident  to  automobile  traffic,  has  brought  to  the  forefront  the  use  of  concrete 
to  produce  permanent  construction,  not  only  for  sidewalks  and  pavements,  but 
for  highway  structures,  such  as  bridges,  retaining  walls,  culverts,  and  the 
many  smaller  details,  the  repairs  to  which  are  continually  vexing  the  City 
and  Town  Engineer  and  the  Highway  Commissioner. 

The  purpose  of  the  present  volume,  then,  is  to  present  to  those  in  charge  of 
street  and  highway  construction  and  maintenance,  examples  of  work  which 
have  been  satisfactorily  performed,  and,  further,  to  give  drawings  and  designs 
made  especially  for  The  "ATLAS"  Portland  Cement  Company,  either  as 
reproductions  of  existing  structures,  from  drawings  and  photographs  kindly 
furnished  by  the  local  authorities,  or  as  original  designs  prepared  by  expert 
engineers  at  the  request  of  the  "ATLAS"  Portland  Cement  Company. 

The  most  important  matter  of  sidewalk  construction  is  taken  up  in  con- 
siderable detail,  while  concrete  street  pavement  construction  has  been  thor- 
oughly investigated,  and  recommendations  made  of  methods  which  have 
produced  durable  and  satisfactory  results.  Numerous  examples  and  sugges- 
tions are  given  in  the  line  of  bridge  design  and  construction,  both  for  arches 
and  flat  bridges;  sewers,  culverts  and  retaining  walls  are  quite  thoroughly 
treated;  and  such  minor  structures  as  drains,  brook  linings,  fences  and  posts, 
are  illustrated  and  described. 


Although  the  information  in  this  little  volume  is  more  valuable  and  in 
much  greater  detail  than  is  customarily  presented  by  manufacturing  com- 
panies, the  position  of  The  "ATLAS"  Portland  Cement  Company  as  the  lead- 
ing cement  manufacturers  in  the  world  has  led  them  to  present  data  which  will 
tend  not  only  toward  an  increasing  use  of  cement  but  toward  a  use  of  cement 
according  to  the  best,  safest  and  most  economical  practice. 

This  present  volume  together  with  the  other  books  of  The  "ATLAS" 
Portland  Cement  Company,  namely,  "Concrete  Construction  About  the  Home 
and  on  the  Farm" ;  "Concrete  Country  Residences" ;  "Reinforced  Concrete  in 
Factory  Construction,"  and  "Concrete  in  Railroad  Construction,"  covers  a 
wide  range  in  the  use  of  concrete. 

THE  ATLAS  PORTLAND  CEMENT  COMPANY. 
New  York,  June,  1909. 


10 


CHAPTER  I. 
CONCRETE. 

During  the  year  1907  the  State  Highway  Commission  of  Massachusetts 
spent  $468,000  in  the  construction  of  new  roads  and  $106,000  for  repairs  and 
maintenance  of  roads  in  its  charge.  The  State  Highway  Department  of  Penn- 
sylvania expended  $3,187,000  in  the  construction  of  new  roads  up  to  January 
i,  1908,  and  in  the  report  of  this  department  for  1907  the  sum  of  $29,225,000 
is  given  as  the  total  cost  of  roads  completed,  under  contract  and  to  be  built. 
Other  States  are  similarly  engaged  in  building  new  roads,  and  improving  old 
ones  so  that  the  movement  for  better  roads  and  streets  is  almost  universal. 
Such  enormous  costs  of  construction  and  maintenance  show  the  necessity  for 
the  selection  of  materials  which,  in  the  long  run,  are  the  cheapest  and  most 
economical. 

Concrete  is  playing  a  large  part  in  this  construction  and  re-construction, 
not  so  much  in  the  roadbed  proper,  although  as  is  shown  in  the  pages  which 
follow,  concrete  street  pavements  are  well  adapted  to  certain  conditions,  but 
especially  for  the  various  structures  which  are  necessarily  incidental  to  road 
building. 

This  class  of  work  includes  not  only  such  structures  as  are  necessary  in 
first-class  streets  or  highways,  such  as  culverts,  bridges  and  retaining  walls, 
but  also  in  the  roadway  itself,  either  as  a  foundation  for  a  stone,  brick  or 
asphalt  surface,  or  as  a  complete  pavement  including  foundations  and  wearing 
surfaces. 

For  smaller  uses  concrete  has  a  still  wider  field.  For  sidewalks,  curbs  and 
gutters  its  use  is  becoming  quite  universal,  while  as  a  material  for  drain  tiles, 
lamp  posts  of  various  styles,  hitching  posts,  fence  posts,  and  many  other 
highway  appurtenances,  its  value  is  fast  being  recognized  as  is  shown  by  the 
enormous  increase  in  its  use  for  such  purposes.  As  a  material  for  building 
park  structures,  such  as  bridges,  buildings,  drinking  fountains,  and  seats,  con- 
crete is  well  suited  because  of  its  cheapness,  durability,  and  the  ease  with 
which  it  is  molded  into  artistic  designs. 

In  the  larger  structures  such  as  bridges  and  retaining  walls,  especially 
where  steel  reinforcement  is  necessary  to  give  the  required  strength,  a  proper 
design  with  good  working  drawings  showing  the  dimensions  and  the  location 
of  the  steel  is  of  the  utmost  importance,  and  where  the  structure  is  of  appre- 

ii 


ciable  size  a  competent  engineer  familiar  with  the  principles  of 'design  and 
with  practical  construction  in  concrete  should  be  employed  to  prepare  plans 
and  specifications,  and  to  superintend  the  construction.  On  the  other  hand, 
many  of  the  minor  details  can  be  built  with  but  little  engineering  experience, 
provided  directions  given  by  competent  authorities  are  carefully  followed, 
and  good  judgment  is  used  in  the  selection  of  the  materials  and  in  the  work 
of  construction. 

The  principal  requisites  of  a  material  used  in  building  various  structures 
forming  the  necessary  parts  of  a  well-constructed,  modern  highway  are  cheap- 
ness and  durability.  If  the  first  cost  of  the  structure  is  to  be  small  the  mate- 
rials used  in  its  construction  must  be  cheap  and  must  be  easily  placed  in  posi- 
tion by  ordinary  workmen,  and  if  the  cost  of  maintenance  is  not  to  be  excess- 
ive the  materials  used  must  possess  qualities  that  will  enable  them  to  with- 
stand the  elements  successfully.  Wood,  steel,  stone,  and  concrete  are  in 
general  the  principal  materials  used  in  the  construction  of  highway  appur- 
tenances such  as  bridges,  culverts,  sidewalks,  curbs,  and  gutters.  Of  these 
four  materials  wood  is  usually  the  cheapest  in  first  cost  for  small  structures 
and  is  the  least  durable  of  all.  The  cost  of  maintenance  of  ordinary  wooden 
bridges  is  so  great  and  the  life  is  so  short  that  wood  is  really  no  longer  con- 
sidered seriously  as  a  material  for  first-class  construction,  especially  in  those 
localities  where  lumber  is  scarce.  Stone  is  generally  a  durable  material  of 
construction,  but  its  first  cost,  and  in  many  places  its  scarcity,  tend  to  limit 
its  use  for  highway  purposes.  It  is  also  difficult  and  expensive  to  shape  stone 
into  desired  forms  which  in  many  cases  are  required  to  secure  the  best  re- 
sults. The  importance  of  steel  in  the  construction  of  highway  bridges  of  long 
spans  is  well  understood,  but  its  cost  and  the  constant  heavy  maintenance 
charges,  or  its  rapid  deterioration  if  not  properly  maintained,  have  caused 
builders  of  bridges  to  seek  some  other  material  which  is  lower  in  first  cost  and 
which  will  not  require  constant  painting.  Clearly,  concrete,  or  concrete  with 
steel  imbedded  in  it  to  reinforce  it,  is  the  material  above  all  others  that  com- 
bines the  advantages  of  cheapness  and  durability.  Concrete  can  be  made  at 
small  expense  in  practically  any  locality;  can  be  molded  in  any  desired  shape 
or  size;  requires  no  maintenance,  and  can  be  placed  in  position  with  very 
little  skilled  labor. 

In  making  concrete  the  cement,  sand,  and  stone  or  gravel  should  be  care- 
fully chosen,  thoroughly  mixed,  and  properly  laid.  If  these  precautions  are 
taken  the  mass  will  begin  to  stiffen  in  an  hour  or  so  after  being  laid  and  will 
continue  to  harden  until  in  about  one  month's  time  the  mass  becomes  a  hard 
compact  stone. 


12 


CEMENT. 

Portland  cement  of  first-class  reputation  should  be  used  to  obtain  the 
greatest  uniformity,  reliability  and  the  highest  strength.  If  the  work  is  small 
and  unimportant  and  a  brand  of  cement  of  first-class  reputation  is  purchased 
from  a  reliable  dealer  no  testing  is  necessary,  but  for  important  structures  the 
cement  should  be  tested  and  should  meet  the  requirements  of  the  American 
Society  for  Testing  Materials.*  If  it  is  impracticable  to  make  these  complete 
tests,  specimens  may  be  made  to  see  if  the  cement  sets  up  properly.  The 
following,  also,  is  a  simple  test  for  determining  the  soundness  of  the  cement : 

A  sound  cement  will  not  crumble  when  placed  in  the  work  and  a  test  for 
soundness  is  therefore  of  considerable  importance.  Oftentimes  no  other  test 
need  be  made.  Mix,  by  kneading  i^  minutes,  one  cupful  of  Portland 
cement  with  enough  water  to  form  a  paste  having  a  consistency  like  that 
of  ordinary  putty.  Place  part  of  this  paste  on  each  of  3  pieces  of  glass  about 
4  inches  square  so  as  to  make  a  pat  about  3  inches  in  diameter  and  */£  inch 
thick  at  the  center  tapering  down  to  a  thin  edge.  Leave  these  3  pats  under 
a  damp  cloth  arranged  so  that  it  will  not  touch  them  for  24  hours.  Then 
place  one  pat  in  air  at  an  ordinary  temperature  for  28  days,  a  second  pat  in 
water  for  28  days,  and  the  third  pat  in  a  tightly  closed  vessel  over  boiling 
water  for  5  hours.  If  the  cement  is  of  good  quality  the  pats  will  show  no 
radial  cracks  and  they  will  not  crumble.  If  the  time  is  limited  and  the  pat 
placed  in  steam  shows  no  signs  of  crumbling  the  cement  may  be  accepted 
on  this  steam  test  alone. 

Portland  cement  is  manufactured  from  a  mixture  of  two  materials,  one  of 
them  a  rock  like  limestone  or  a  softer  material  like  chalk  which  is  nearly  pure 
dime,  and  another  material  like  shale,  which  is  a  hardened  clay,  or  else  clay 
itself.  In  other  words,  there  must  be  one  material  which  is  largely  lime  and 
another  material  which  is  largely  clay,  and  these  two  must  be  mixed  in  very 
exact  proportions  determined  by  chemical  tests,  the  proportions  of  the  two 
being  changed  every  few  hours  to  allow  for  the  variation  in  the  chemical  com- 
position of  the  materials. 

"ATLAS"  Portland  Cement  is  made  by  quarrying  each  of  these  materials, 
crushing  them  separately,  mixing  them  in  the  exact  proportions,  and  grinding 
them  to  a  very  fine  powder.  This  powder  is  fed  into  long  rotary  kilns,  which 
are  iron  tubes  about  5  or  6  feet  in  diameter  lined  with  fire  brick  and  over  100 
feet  long.  Powdered  coal  is  also  fed  into  the  kilns  and  burned  at  a  tempera- 
ture of  about  3,000  deg.  Fahr.,  a  temperature  higher  than  that  needed  to  melt 
iron  to  a  liquid  and  there  is  formed  what  is  called  cement  clinker,  a  kind  of 
dark  porous  stone  which  looks  almost  exactly  like  lava. 


*These  may  be  obtained  by  addressing  The  Atlas  Portland  Cement  Company. 

13 


After  leaving  the  kiln,  the  clinker  is  cooled,  crushed,  and  ground  again  to  a 
still  finer  powder,  so  fine,  in  fact,  that  most  of  the  particles  are  less  than  1/200 
of  an  inch  in  size,  and  this  grinding  produces  the  light  gray-colored  powder 
characteristic  of  "ATLAS"  Portland  Cement. 

It  is  now  placed  in  storage  tanks  or  stock  houses  where  it  should  remain 
for  a  while  to  season  before  it  is  put  into  bags  or  barrels  and  shipped.  The 
barrels  weigh  400  pounds  gross,  or  376  pounds  net.  When  shipped  in  bags 
the  weight  is  94  pounds  per  bag,  four  bags  being  equal  to  one  barrel. 

At  the  "ATLAS"  plants  from  the  time  the  rock  is  taken  from  the  quarry 
until  it  is  packed  in  barrels  or  bags  all  of  the  work  is  done  by  machinery,  and 
a  thorough  chemical  mixture  takes  place  regulated  by  the  experienced  chem- 
ists in  charge  of  the  work. 

STORING  CEMENT. 

Cement  should  come  packed  in  barrels  or  in  stout  cloth  or  canvas  bags  and 
should  be  stored  in  a  dry  place,  preferably  a  house  or  shed  until  used,  or  if  no 
such  storage  house  is  available  the  cement  should  be  placed  on  a  wooden  plat- 
form raised  at  least  6  inches  above  the  ground  and  should  be  covered  so  as  to 
exclude  water.  When  used  the  cement  should  be  free  from  lumps. 

SAND   OR  FINE  AGGREGATE. 

The  term  aggregate  includes  the  stone  and  sand  in  concrete  and  may  be 
classified  as  fine  and  coarse.  The  fine  aggregate  may  be  sand  or  crushed  stone 
or  gravel  screenings  which  will  pass  when  dry  a  screen  having  *4  inch  diam- 
eter holes.  If  sand  is  used  it  should  be  clean  and  coarse,  or  a  mixture  of  coarse 
and  fine  grains  with  the  coarse  grains  predominating.  It  should  be  free  from 
loam,  clay,  mica,  sticks,  fine  roots,  or  other  impurities.  Sand  should  be  coarse, 
that  is,  it  should  have  a  considerable  portion  of  its  grains  measuring  1/32  to 
%  inch  in  diameter  and  should  the  grains  run  up  to  *4  inch  the  strength  of  the 
mortar  is  increased. 

Vegetable  loam  is  frequently  very  injurious  to  concrete  and  great  care 
should  be  taken  in  selecting  and  excavating  to  see  that  the  sand  does  not  con- 
tain any  vegetable  matter.  For  all  important  structures  the  sand  should  be 
tested  in  a  laboratory  as  described  in  the  following  paragraphs : 

"Mortars  composed  of  one  part  Portland  cement  and  three  parts  fine  aggre- 
gate by  weight  when  made  into  briquets  should  show  a  tensile  strength  of  at 
least  70  per  cent  of  the  strength  of  1 13  mortar  of  the  same  consistency  made 
with  the  same  cement  and  standard  Ottawa  sand.  To  avoid  the  removal  of 
any  coating  on  the  grains  which  may  affect  the  strength,  bank  sands  should 
not  be  dried  before  being  made  into  mortar  but  should  contain  natural  mois- 

14 


ture.  The  percentage  of  moisture  may  be  determined  upon  a  separate  sample 
for  correcting  weight  of  the  sand.  From  10  to  40  per  cent  more  water  may  be 
required  in  mixing  bank  or  artificial  sands  than  for  standard  Ottawa  sand  to 
produce  the  same  consistency."* 

"The  relative  strength  of  mortars  from  different  sands  is  largely  affected  by 
the  size  of  the  grains.  A  coarse  sand  gives  a  stronger  mortar  than  a  fine  one, 
and  generally  a  gradation  of  grains  from  fine  to  coarse  is  advantageous.  If  a 
sand  is  so  fine  that  more  than  10  per  cent  of  the  total  dry  weight  passes  a  No. 
100  sieve,  that  is,  a  sieve  having  100  meshes  to  the  linear  inch,  or  if  more  than 
35  per  cent  of  the  total  dry  weight  passes  a  sieve  having  50  meshes  per  linear 
inch,  it  should  be  rejected  or  used  with  a  large  excess  of  cement."* 

Crushed  stone  or  gravel  screenings,  when  used  in  place  of  sand,  should  pass 
when  dry  a  screen  having  ^4-inch  diameter  holes  or  a  screen  having  4  meshes 
to  the  linear  inch  and  if  free  from  impurities  may  be  substituted  for  a  part  or 
the  whole  of  the  sand  in  such  proportions  as  to  give  a  dense  mixture. 

COARSE   AGGREGATE 

Gravel  or  crushed  stone  of  a  hard  and  durable  quality  make  up  the  coarse 
aggregate  for  concrete.  The  best  materials  are  trap  rock,  hard  limestone, 
granite,  or  conglomerate  of  size  retained  on  a  screen  having  ^-inch  diameter 
holes. 

Aggregates  containing  soft,  flat,  or  elongated  particles  should  be  excluded 
from  important  structures.  Stone  which  breaks  into  cubical  or  similar  angu- 
lar forms  is  much  preferable  in  any  case  to  that  which  breaks  into  flat  layers 
because  it  gives  a  stronger  concrete  and  one  which  is  more  readily  placed. 
Graded  sizes  of  particles,  that  is,  particles  varying  from  small  to  large  sizes,  are 
generally  advantageous.  Where  concrete  is  used  in  mass,  the  crushed  stone  or 
gravel  may  range  in  size  from  %  inch  to  that  which  passes  through  a  3-inch 
ring.  For  reinforced  concrete,  the  particles  must  be  small  enough  to  flow  into 
place  around  and  between  the  steel  bars  and  into  all  corners  of  the  forms.  For 
this  a  maximum  size  of  i  inch  (that  is,  the  largest  particle  small  enough  to  go 
through  a  i-inch  ring),  or  in  other  cases  a  s^-inch  or  ^-inch  must  be  used. 
The  material  passing  the  %-inch  screen  may  be  used  as  a  part  of  the  sand. 

If  gravel  is  used  instead  of  crushed  stone,  it  should  be  of  a  size  to  be  easily 
handled  and  easily  placed  around  the  steel  if  there  is  steel  reinforcement  and 
it  should  be  clean  and  free  from  vegetable  or  other  deleterious  matter.  As  in 
the  case  of  crushed  stone,  the  material  below  ^4  inch  in  size  should  be  screened 
out  to  be  used  as  sand.  Sand  and  gravel  are  rarely  found  mixed  in  the  proper 


*Report    of    Committee    on    Reinforced    Concrete,    1909,    National    Association    of 
Cement  Users. 


proportions  in  the  natural  bank,  and  it  is  cheaper  to  screen  and  remix  them  in 
the  correct  proportions  than  to  use  the  richer  mixture  necessary  with  un- 
screened material. 

Pebbles  of  graded  sizes  with  the  larger  sizes  predominating  are  preferable 
to  pebbles  of  a  uniform  size  because  they  are  more  readily  mixed  and  placed. 

For  important  structures  and  for  structures  where  there  will  be  considerable 
wear  on  the  concrete,  the  materials  should  be  carefully  selected,  but  for  unim- 
portant structures  it  is  usually  sufficient  to  make  two  small  blocks  of  concrete, 
say  6-inch  cubes,  and  place  one  of  these  cubes  out-of-doors  in  air  for  7  days 
and  the  other  in  a  fairly  warm  room. 

The  specimen  placed  in  the  warm  room  should  be  hard  enough  at  the  end 
of  24  hours  to  bear  pressure  from  the  thumb  without  indentation  and  it  also 
should  whiten  out  to  some  extent  during  this  time.  The  specimen  placed  out- 
of-doors  should  be  hard  enough  to  remove  from  the  mold  at  the  end  of  24 
hours  in  ordinary  mild  weather  or  48  hours  in  cold  damp  weather.  At  the  end 
of  a  week  test  both  blocks  by  hitting  them  with  a  hammer.  If  the  hammer 
does  not  dent  them  under  light  blows  such  as  would  be  used  in  driving  tacks 
and  the  blocks  sound  hard  and  are  not  broken  under  these  blows  the  sand  as  a 
general  rule  can  be  used. 

WATER. 

Water  used  in  mixing  concrete  should  be  free  from  oil,  acids,  alkalies,  or 
vegetable  matter. 

PROPORTIONS  OF  MATERIALS. 

The  following  paragraphs  relating  to  the  proper  proportions  of  materials 
for  making  concrete  are  taken  from  "Concrete  Construction  About  the  Home 
and  on  the  Farm" :  * 

"Concrete  is  composed  of  a  certain  amount  or  proportion  of  cement,  a  larger 
amount  of  sand,  and  a  still  larger  amount  of  stone.  The  fixing  of  the  quanti- 
ties of  each  of  these  materials  is  called  proportioning.  The  proportions  for  a 
mix  of  concrete  if  given,  for  instance,  as  one  part  of  cement  to  two  parts  of 
sand  to  four  parts  of  stone  or  gravel,  are  written  1 12  14,  and  this  means  that 
one  cubic  foot  of  packed  cement  is  to  be  mixed  with  two  cubic  feet  of  sand  and 
with  four  cubic  feet  of  loose  stone. 

"For  ordinary  work,  use  twice  as  much  coarse  aggregate  (that  is,  gravel  or 
stone)  as  fine  aggregate  (that  is,  sand). 

"If  gravel  from  a  natural  bank  is  used  without  screening,  use  the  same  pro- 
portions called  for  of  the  coarse  aggregate ;  that  is,  if  the  specifications  call  for 
proportions  of  1 12  .-4,  as  given  above,  use  for  unscreened  gravel  (provided  it 


*Published   by   The   Atlas   Portland  Cement  Company,   from  whom  it  can  be  ob- 
tained by  making  application  for  same. 

16 


contains  quite  a  large  quantity  of  stone)  one  part  cement  to  four  parts  un- 
screened gravel. 

"If  when  placing  concrete  with  the  proportions  specified,  a  wall  shows 
many  voids  or  pockets  of  stone,  use  a  little  more  sand  and  a  little  less  stone 
than  called  for.  If  on  the  other  hand,  when  placing,  a  lot  of  mortar  rises  to  the 
top,  use  less  sand  and  more  stone  for  the  next  batch. 

"In  calculating  the  amount  of  each  of  the  materials  to  use  for  any  piece  of 
work,  do  not  make  the  mistake  so  often  made  by  the  inexperienced  that  one 
barrel  of  cement,  two  barrels  of  sand,  and  four  barrels  of  stone,  will  make 
seven  barrels  of  concrete.  As  previously  stated,  the  sand  fills  in  the  voids  be- 
tween the  stones,  while  the  cement  fills  the  voids  between  the  grains  of  sand, 
and  therefore  the  total  quantity  of  concrete  will  be  slightly  in  excess  of  the 
original  quantity  of  stone." 

The  unit  of  measure  is  the  barrel,  which  should  be  taken  as  containing  3.8 
cubic  feet.  Four  bags  containing  94  pounds  of  cement  each  are  equivalent  to 
one  barrel.  Sand  and  stone  or  gravel  should  be  measured  separately  as  loosely 
thrown  into  the  measuring  receptacle. 

The  following  quotation  from  ''Concrete,  Plain  and  Reinforced"*  by  the 
well-known  authorities,  Taylor  and  Thompson,  is  printed  as  a  guide  to  those 
who  wish  to  build  any  concrete  structure  for  which  specific  instructions  are 
not  given  in  the  following  pages : 

"As  a  rough  guide  to  the  selection  of  materials  for  various  classes  of  work, 
we  may  take  four  proportions  which  differ  from  each  other  simply  in  the  rela- 
tive quantity  of  cement" : 

(a)  A  Rich  Mixture  for  columns  and   other  structural  parts  subjected  to  high 
stresses  or  requiring  exceptional  water  tightness:       Proportions — 1:1^:3;  that   is, 
one  barrel  (4  bags)  packed  Portland  cement  to  iT/2  barrels  (5.7  cubic  feet)  loose 
sand  to  3  barrels  (11.4  cubic  feet)  loose  gravel  or  broken  stone. 

(b)  A  Standard   Mixture  for  reinforced  floors,  beams  and   columns,  for  rein- 
forced  engine   or   machine  foundations   subject   to   vibrations,    for   tanks,   sewers, 
conduits,   and   other  water-tight   work:     Proportions — 1:2:4;    that  is,    one   barrel 
(4  bags)   packed  Portland  cement  to  2  barrels   (7.6  cubic  feet)   loose  sand  to  4 
barrels  (15.2  cubic  feet)  loose  gravel  or  broken  stone. 

(c)  A  Medium  Mixture  for  ordinary  machine  foundations,  retaining  walls,  abut- 
ments, piers,  thin  foundation  walls,  building  walls,  ordinary  floors,  sidewalks,  and 
sewers   with   heavy   walls:  Proportions — 1:2^:5;    that    is,    one    barrel     (4    bags) 
packed  Portland  cement  to  2T/^  barrels   (9.5    cubic    feet)    loose    sand   to    5   barrels 
(19  cubic  feet)  loose  gravel  or  broken  stone. 

(d)  A  Lean  Mixture  for  unimportant  work  in  masses,  for  heavy  walls,  for  large 
foundations   supporting   a   stationary   load,   and   for   backing   for  stone   masonry: 
Proportions — 1:3:6;   that   is,   one   barrel    (4  bags)    packed  Portland   cement   to  3 
barrels  (11.4  cubic  feet)  loose  sand  to  6  barrels   (22.8  cubic  feet)  loose  gravel  or 
broken  stone. 

*See  reference,  footnote,  page  18. 

17 


QUANTITIES  OF  MATERIALS  IN  CONCRETE. 

In  estimating  the  quantities  of  cement,  sand,  and  broken  stone  or  gravel  in 
a  given  volume  of  concrete  or  in  estimating  the  volume  of  mortar  or  concrete 
which  can  be  made  from  one  barrel  of  cement  the  three  accompanying  tables 
will  be  found  useful.  The  values  given  in  the  tables  are  computed  from  results 
of  actual  experiments  and  have  been  checked  with  concrete  laid  in  large  masses. 


VOLUME  OF  CONCRETE  MADE  FROM  ONE  BARREL  OF  PORTLAND  CEMENT* 
Based  on  a  Barrel  of  3.8  Cubic  Feet 


Volume  of 

Average  Volume  of  Rammed 
Concrete  Made  From  One 

Proportions 
by  Parts 

Proportions 
by  Volume 

Mortar  in 
Terms  of 

Barrel  of  Cement 

Percentage 
of  Volume 
of 

Percentages    of   Voids   in 
Broken  Stone  or  Gravel 

Cem't 

Sand 

Stone 

Cem't 

Sand 

Stone 

Stone 

50%t 

45%t 

40%§ 

bbl. 

cu.  ft. 

cu.  ft. 

per  cent. 

cu.  ft. 

cu.  ft. 

cu.  ft. 

1 

1 

2 

1 

3.8 

7.6 

75 

9.5             9.9           10.3 

1 

1 

3 

1 

3.8 

11.4 

51 

11.5           12.2           12.8 

1 

1H 

3 

1 

5.7 

11.4 

64 

12.9           13.5           14.1 

1 

1^ 

3^ 

! 

5.7 

13.3                 55 

13.9 

14.6           15.4 

1 

2 

3 

1 

7.6 

11.4                 75 

14.3 

14.9           15.5 

1 

2 

4 

1 

7.6 

15.2                 57 

16.3 

17.2           18.0 

1 

2M 

±y* 

1 

9.5 

17.1 

60 

18.7 

19.6           20.6 

1 

2^ 

5 

1 

9.5 

19.0 

54 

19.8 

20.8 

21.8 

1 

3 

5 

1 

11.4 

19.0 

61 

21.1 

22.1 

23.2 

1 

3 

6 

1 

11.4 

22.8 

52 

23.2 

24.4 

25.6 

Note. — Variations  in  the  fineness  of  the  sand  and  the  compacting  of  the  concrete  may  effect  the  volumes  by 
10%  in  either  direction. 

tUse  50%  column  for  broken  stone  screened  to  uniform  size. 

jllse  45%  column  for  average  conditions  and  for  broken  stone  with  dust  screened  out. 

§Use  40%  column  for  gravel  or  mixed  stone  and  gravel. 


*Taken  by  permission  from  Taylor  &  Thompson's  "Concrete,  Plain  and  Reinforced," 
copyright,  1905,  by  Frederick  W.  Taylor.    John  Wiley  &  Sons,  New  York,  publishers. 

18 


QUANTITIES  OF  MATERIALS  FOR  ONE  CUBIC  YARD  OF  RAMMED  CONCRETE* 
Based  on  a  Barrel  of  3.8  Cubic  Feet 

Percentages  of  Voids  in  Broken  Stone  or  Gravel 
Volume  of 

I 

I 
S 

v>s 

<u 

1 

^SJSS    £212!    £S2£    S£ 

C~  O5  00        00  t»  00        t-  CD  CD        00  00 

N0te.—  Variations  in  the  fineness  of  the  sand  and  the  compacting  of  the  concrete  may  effect  the  quantities  by  10%  in  either  direction. 
tUse  50%  columns  for  broken  stone  screened  to  uniform  size. 
JUse  45%  columns  for  average  conditions  and  for  broken  stone  with  dust  screened  out. 
§Use  40%  columns  for  gravel  or  mixed  stone  and  gravel. 
*Quoted  from  Copyrighted  Treatise;  see  footnote  on  opposite  page. 

3000     odd     odd     do 

0 

1 

5 

*1 

*E.b-  OO        C~  O5  <N        O5  CD  ••*        OS  Tfl 
^COWtf        COTH^H        'tfrH'tf        TUT* 

^ddd     odd     odd     do 

o 

•CN<NiH        CO-^O        O  rH  •<*        t-lO 
StO'HO        l>  t-  U3        TH  CO  N        r-IO 

•°  N  N  i-J         rH  »-I  rH         rH  rH  i-J         rH  rH 

1 

% 

OH 

to 

^ 

•M- 

0) 

a 

o 

w 

^C-  -^rH        THCOOO        (NC-CO        <O*H 
t—^G)CG        G3  t>  00        OOOOO)        OOO) 

sddd     odd     odd     do 
o 

1 

1>.00  rH<N        O5THTt<        iHCOO        C3b- 
CO  CO"*        COlO-^        U3Tl<Ti<        IQ*# 

^o'dd     odd     odd     do* 
o 

41 

•  CO  N  O        ^H  iH  C-        «O  t-  O        N  iH 

SIXNO      ooooio     THCOCO      (NTH 

-°  (N  (N  CN         rH  rH  rH         rH  rH  rH         rH  rH 

1 

O 

I 

g 

H  — 

<a 

d 

i 
I 

*>.O  O>00        tOOCO       OrHtO        OOO 
00  OJOO        OOOO        OOOOi        OC5 

^ddd     odd     odd     do 

o 

^88S    5IS^    SS^    S5 

a  odd     odd     odd     do 
o 

+j 

ig 
°s 

•  lOTflcs      rf<  oj  10     <M  Tt<  r-      oo«o 

^OOCOO        OiOOtO        »OTl<CO        CQ  rH 

•^(NOQCq         rHrHrH         rHrHrH         rHrH 

Proportions  by  Volume  Mortar  m 
Terms  of 
Percent- 
age of 

<4H 

o 
«u  u 

sg 

|" 

0)    0) 

II 

l-JCO 

8fg 

§g 

^Cfl 

^Wi-H^        lOlOt-        CD  O  ^        rHOQ 

"t-ioco      ioi>»o      epcoio      co  10 

<D 

&( 

•ScOTjI'SH        CO  ^  N        C3  rH  O        OOO 

t-  rH  rH         CO  rH  IO         IO  t-  O>         O5  00 
3         rHrH         rH  rH  rH         rHrHrH         rH  OQ 
O 

"SoOOOt-        t-  CD  CO        IO  IO  IO        Til  ^ 

•COCOIO        IO  t-  t-        O5OJO5        rHrH 
g                                                                               rHrH 

Packed 
Cement 

STHrHrH         rHrHrH         rHrHrH         rHrH 
& 

1 

S, 

>> 

J3 

z 

O 
'43 

I 

& 

o> 
a 
o 

(/} 

^\                           ^ 

CNCOCO      coeoTjt     Ti«^io      weo 

1 

•a 

1 

^     ^             ^^^ 

rHrHrH         rH  N  N         (N  CO  <N         COCO 

•M 

A] 

rHrHrH        rHrHrH        rHrHrH        rHrH 

VOLUME  OF  PLASTIC  MORTAR  MADE  FROM  DIFFERENT  PROPORTIONS  OF  CEMENT 

AND  SAND* 
Quantities  of  Materials  per  Cubic  Yard 


LPropo 


Relative 
©portions  by 
olumef 


Volume  of  Compacted  Plastic 
Mortar 


Materials  for  1  cu.  yd.  Compacted 

Plastic    Mortar,  Based    on    Barrel 

of  3.8  Cubic  Feet 


Cement 

Sand 

From  1  cu.  ft.  Ce- 
ment, Based  on 
Portland  Cement 
Weighing  100 
Lbs.  per  cu.  ft. 

From  1  bbl., 
or  4  bags,  Ce-                Packed 
ment,  Based  on              Cement 
Barrel  of  3.8  cu.  ft. 

Loose 

Sand 

cu.  ft. 

cu.  ft. 

bbl. 

cu.  yd 

1 

0 

0,86 

3.2 

8.31 

1 

1 

1.42 

5.4 

5.01 

0.71 

1 

IK 

1.78 

6.7 

4.00 

0.84 

1 

2 

2.14 

8.1 

3.32 

0.93 

1 

VA 

2.50 

9.5 

2.84 

1.00 

1 

3 

2.86 

10.9                           2.48 

1.05 

Note.— Variations  in  the  fineness  of  the  sand  and  the  cement,  and  in  the  consistency  of  the  mortar  may  affect 
the  values  by  10%  in  either  direction. 
*See  reference,  footnote,  p.  18. 
fCement  as  packed  by  manufacturer,  sand  loose. 

RUBBLE  CONCRETE. 

Rubble  concrete  is  ordinary  concrete  in  which  are  imbedded  large  stones, 
usually  of  a  size  that  can  be  handled  by  one  or  two  men,  but  in  very  massive 
work  such  as  large  dams,  stones  of  even  greater  size  as  heavy  as  can  be  han- 
dled with  a  derrick  are  used.  Only  in  massive  structures  such  as  heavy  foun- 
dations, dams,  retaining  walls,  or  similar  works  is  this  form  of  construction 
possible  and  when  stones  are  imbedded  in  the  concrete  they  should  be  spaced 
at  least  3  inches  from  one  another  and  also  from  the  outer  surface.  About  20 
per  cent  of  the  total  volume  of  the  structure  may  be  replaced  by  "one-man" 
and  "two-men"  stones,  and  thus  a  considerable  saving  in  cost  is  effected  in 
large  structures. 

MIXING  CONCRETE. 

Mixing  may  be  done  either  by  hand  or  machine  and  the  method  to  be  em- 
ployed is  determined  principally  by  the  size  of  the  job.  If  a  small  amount  of 
concrete  is  to  be  made,  hand  mixing  is  the  more  economical,  while  for  large 
works  machine  mixers  are  better  and  generally  cheaper,  though  in  some  cases 
where  the  mixer  must  be  frequently  moved,  hand  mixing  may  prove  to  be  the 
cheaper.  A  better  and  more  uniform  concrete  can  be  made  with  a  good  ma- 


20 


chine  mixer  than  by  hand.  The  type  of  mixer  should  be  such  as  to  insure  a 
thorough  and  uniform  mixing  of  the  materials.  In  any  case  enough  water 
should  be  used  to  make  a  mushy  consistency  which  requires  very  little  tamp- 
ing to  bring  the  mortar  to  the  surface. 

HAND  MIXING. 

If  hand  mixing  is  employed  it  should  be  carefully  done  on  a  water-tight 
platform  and  should  be  subjected  to  thorough  supervision.  The  following  di- 
rections by  Taylor  and  Thompson  for  hand  mixing  will  be  found  useful  to 
those  who  are  inexperienced  in  this  class  of  work.* 


here 


FIG.  1.— POSITION  OF  MEN  AND  CONCRETE  ON  PLATFORM  WHILE  TURNING.* 

"Assume  a  gang  of  four  men  to  wheel  and  mix  the  concrete  with  two  other 
men  to  look  after  the  placing  and  ramming. 

"When  starting  a  batch,  two  mixers  shovel  or  wheel  sand  into  the  measur- 
ing box  or  barrel — which  should  have  no  bottom  or  top — level  it  and  lift  off 
the  measure,  leveling  the  sand  still  further  if  necessary.  They  then  empty 
the  cement  on  top  of  the  sand,  level  it  to  a  layer  of  even  thickness,  and  turn 
the  dry  sand  and  cement  with  shovels  three  times,  as  described  below,  after 
which  the  mixture  should  be  of  uniform  color. 

>  "While  these  two  men  are  mixing  sand  and  cement,  the  other  two  fill  the 
gravel  measure  about  half  full,  then  the  two  sand  men  take  hold  with  them, 
and  complete  filling  it.  The  gravel  measure  is  lifted,  the  gravel  hollowed  out 
slightly  in  the  center,  and  the  mixture  of  sand  and  cement  shoveled  on  top  in 
a  layer  of  nearly  even  thickness.f  A  definite  number  of  pails  are  filled  with 


*See  reference,  footnote,  page  18. 

t"Some  Engineers  prefer  to  spread  the  stone  on  top  of  the  sand  and  cement,  while 
others  prefer  to  mix  the  water  with  the  sand  and  cement  before  adding  them  to  the 
stone." 


21 


water,  and  poured  directly  on  the  top  of  these  layers,  greater  uniformity  being 
thus  attained  than  by  adding  the  water  directly  from  a  hose.  After  soaking 
in  slightly  the  mass  is  ready  for  turning. 

"The  method  illustrated  in  Fig.  i  of  turning  with  shovels  materials  which 
have  already  been  spread  in  layers  is  as  follows : 

"Two  men,  A  and  B,  with  square-pointed  shovels,  stand  facing  each  other 
at  one  end  of  the  pile  to  be  turned,  one  working  right-handed  and  the  other 
left-handed.  Each  man  pushes  his  shovel  along  the  platform  under  the  pile, 
lifts  the  shovelful,  turns  with  it,  and  then,  turning  the  shovel  completely  over, 
and  with  a  spreading  motion  drawing  the  shovel  toward  himself,  deposits  the 
material  about  2  feet  from  its  original  position.  Repetitions  of  this  operation 
will  form  a  flat  ridge  of  the  material,  on  a  line  with  the  pile  as  it  originally 
lay,  and  flat  enough  so  that  the  stones  will  not  roll.  As  soon  as,  but  not  be- 
fore, a  single  ridge  is  complete,  two  other  men,  C  and  D,  should  start  upon 
this  ridge,  turning  the  materials  for  the  second  time,  as  shown  in  the  illustra- 
tion, and  forming  as  before  a  flat  ridge  and  finally  a  level  pile  which  gradually 
replaces  the  last.  A  third  mixing  is  accomplished  in  a  similar  way. 

"Fig.  i  gives  the  position  of  the  piles  as  the  concrete  is  being  turned.  A 
portion  of  the  original  layers  is  shown  at  P,  the  ridge  formed  by  men  A  and 
B  shoveling  from  pile  P  is  shown  at  Q,  and  the  beginning  of  the  ridge  formed 
by  men  C  and  D  is  shown  at  RR.  The  third  turning  is  not  shown. 

''The  quantity  of  water  used  must  be  varied  according  to  the  moisture  in 
the  materials  and  the  consistency  required  in  the  concrete.  While  the  opin- 
ions of  engineers  regarding  the  proper  consistency  vary  widely,  it  is  advisable, 
the  authors  believe,  for  an  inexperienced  gang  to  use  an  excess  of  water.  The 
rule  may  be  made  in  hand  mixing  to  use  as  much  water  as  can  be  thoroughly 
incorporated  with  the  materials.  Concrete  thus  made  will  be  so  soft  or 
'mushy'  that  it  will  fall  off  the  shovel  unless  handled  quickly. 

"After  the  material  has  been  turned  twice,  as  described,  and  as  soon  as  the 
third  turning  has  been  commenced,  two  of  the  mixers  who  have  finished  turn- 
ing may  load  the  concrete  into  barrows  and  wheel  to  place.  They  should  fill 
their  own  barrows,  and  after  the  mass  has  been  completely  turned  for  the 
third  time  by  the  other  two  men  the  latter  should  start  filling  the  gravel 
measure  for  the  next  batch. 

"If  the  concrete  is  not  wheeled  over  50  feet,  four  experienced  men  ought 
to  mix  and  wheel  on  the  average  about  10^2  batches  in  ten  hours.  This  figure 
is  based  on  proportions  1 12  1/2 15,  and  assumes  that  a  batch  consists  of  one 
barrel  (four  bags)  Portland  cement  with  9.5  cubic  feet  of  sand  and  19  cubic 
feet  of  gravel  or  stone. 

22 


"Assuming  that  1.29  barrels  of  cement  are  required  for  i  cubic  yard  of 
concrete,  one  barrel  of  cement — that  is,  one  batch — will  make  0.78  cubic  yard 
of  concrete;  hence  10^  batches  mixed  and  wheeled  by  four  men  in  ten  hours 
are  equivalent  to  8%  cubic  yards  of  concrete.  This  is  for  the  very  simplest 
kind  of  concreting  and  makes  no  allowance  for  the  labor  of  supplying  ma- 
terials to  the  mixing  platform  or  for  building  forms." 

PLACING   CONCRETE. 

In  handling  and  placing  concrete,  the  materials  must  remain  perfectly  mixed, 
the  aggregate  must  not  separate  from  the  mortar  and  the  concrete  must  be 
rammed  or  agitated  so  as  to  thoroughly  fill  the  forms  and  surround  all  parts 
of  the  steel  reinforcement.  Care  must  be  taken  to  remove  all  sticks,  blocks, 
shavings,  or  similar  materials  from  the  forms  before  the  concrete  is  placed 
and  in  case  new  concrete  is  deposited  on  a  layer  that  has  already  set,  the  old 
surface  should  be  roughened,  cleaned,  and  drenched  with  water  before  the 
new  material  is  added.  In  reinforced  structures  the  metal  must  be  placed  in 
the  forms  and  wired  or  otherwise  held  rigidly  in  position  before  any  concrete 
is  laid.  It  is  now  generally  customary  to  use  wet  mixtures  and  the  concrete 
is  usually  carried  in  buckets  or  in  water-tight  wheelbarrows.  An  ordinary 
whelbarrow  load  of  concrete  is  about  1.9  cu.  ft.  If  wet  concrete  is  used  it 
can  be  dropped  vertically  into  place  or  run  through  an  inclined  water-tight 
chute.  Concrete  should  be  wet  frequently  for  a  few  days  after  it  is  laid. 


LAYING   CONCRETE   IN   WATER. 

Only  in  exceptional  cases  should  concrete  be  placed  in  water  and  even 
then  the  greatest  care  must  be  taken  to  prevent  the  cement  from  being  washed 
out.  Under  no  circumstances  should  it  be  thrown  or  placed  into  water  by 
shovels.  In  some  cases  of  small  construction,  the  concrete  may  be  deposited 
in  bags,  or  it  may  be  placed  in  pails  with  a  board  covering  the  top  of  the  pail 
and  lowered  carefully  into  the  water  to  the  bottom.  When  this  has  reached 
bottom,  turn  the  pail  upside  down  and  move  the  board  from  underneath  and 
carefully  raise  the  pail,  allowing  the  concrete  to  flow  out.  Great  care  must 
be  taken  not  to  disturb  the  water  in  which  the  concrete  is  being  placed  nor  to 
touch  the  concrete  before  it  has  set.  Under  no  circumstances  should  concrete 
be  placed  in  running  water.  In  large  work,  it  is  sometimes  placed  by  means 
of  a  tube  extending  into  the  water  with  the  lower  end  near  the  bottom.  By 
keeping  a  continuous  flow  of  concrete  passing  through  the  tube,  the  cement 
will  not  be  separated  from  the  aggregate. 

23 


LAYING  CONCRETE  IN  SEA  WATER. 

For  use  in  sea  water  concrete  must  be  proportioned  to  secure  maximum 
density  and  must  be  so  carefully  mixed  and  placed  as  to  secure  an  impervious 
mass.  Unless  proper  precautions  are  taken  in  choosing  the  materials,  mixing, 
and  in  depositing  the  concrete  there  is  danger  of  scaling  on  the  surface  of  the 
concrete  between  high  and  low  water  levels. 

The  remarks  just  made  concerning  the  use  of  concrete  in  sea  water  are 
equally  true  of  concrete  placed  in  alkaline  soils  where  the  mixture  must  be  of 
maximum  density  and  must  be  richer  than  where  used  in  ordinary  soils. 


EFFECT   OF   MANURE. 

Manure,  because  of  the  acid  in  its  composition,  is  injurious  to  green  con- 
crete, but  after  the  concrete  is  thoroughly  hardened  it  satisfactorily  resists 
such  action. 

FREEZING. 

Concrete  for  thin  walls  and  reinforced  concrete  structures  should  not  be 
laid  during  freezing  weather  unless  concrete  is  prevented  from  freezing  by 
warming  the  materials  before  mixing  and  by  covering  the  concrete  after  it  is 
placed  with  a  thick  covering  of  clean  straw,  sand,  or  other  suitable  material. 
Common  salt  is  quite  frequently  used  to  lower  the  freezing  point  of  the  water 
used  in  mixing  concrete.  A  well  known  rule  requires  i  per  cent  by  weight 
of  the  salt  to  the  weight  of  the  water  for  each  degree  Fahrenheit  below  freez- 
ing point  of  water. 

As  one  cannot  tell  in  advance  how  low  the  temperature  is  going  to  fall, 
an  arbitrary  amount  of  salt  must  be  used.  Some  engineers  specify  two  pounds 
of  salt  to  each  bag  of  cement,  and  in  case  this  is  not  sufficient,  three  pounds 
to  a  bag. 

Another  method  is  to  mix  warm  sand  and  stone  with  the  cement  and  water 
in  such  manner  as  will  bring  the  entire  mixture  up  to  about  75  degrees  Fahren- 
heit, protecting  in  the  early  stages  of  setting,  so  far  as  possible,  from  cold 
and  currents  of  air. 

Heavy  walls  and  foundations  where  the  appearance  of  the  faces  is  of  no 
importance  may  be  laid  in  freezing  weather. 

Concrete  sidewalks  must  not  be  laid  in  freezing  weather  for  the  surface 
will  soon  scale. 

24 


FORMS. 

Forms  usually  are  of  wood,  though  in  some  cases  metal  is  used.  They 
must  be  strongly  built  so  as  to  prevent  displacement,  deflection,  or  leakage  of 
mortar  and  they  must  not  be  removed  until  the  concrete  has  set.  The  time 
required  for  setting  varies  with  the  condition  of  the  weather,  longer  time 
being  required  in  cold  or  wet  weather;  with  the  quality  of  the  cement;  and 
with  the  amount  of  water  used  in  mixing.  White  pine  is  the  best  lumber  for 
forms,  but  cheaper  kinds,  such  as  spruce,  fir,  Norway  pine  or  softer  kinds  of 
Southern  pine,  are  frequently  used,  and  green  lumber  is  on  the  whole  better 
than  dry.  To  secure  a  smooth  surface  on  the  finished  concrete,  lumber  planed 
on  one  side  must  be  used ;  likewise  where  the  forms  are  to  be  removed  within 
a  day  or  two,  planed  lumber  must  be  used,  for  then  the  concrete  will  not  stick 
to  the  planks  and  they  may  be  again  used  without  much  cleaning. 

Forms  usually  consist  of  boards  held  in  place  by  studs  braced  so  as  to 
remain  in  place.  For  the  boards  one  or  two-inch  planks  are  commonly  used 


FIG.  2.— FORMS  FOR  BEAM  BRIDGE 

and  quite  frequently  tongued  and  grooved  materials  are  necessary  for  tight 
construction.  The  studs  are  spaced  at  distances  apart  depending  upon  the 
consistency  of  the  concrete,  the  thickness  of  the  wall,  and  the  character  of 
finished  concrete  surface  desired.  Wet  concrete  in  large  masses  is  apt  to 
exert  considerable  pressure  against  the  forms  before  the  cement  sets,  but  with 
wet  concrete  less  ramming  is  necessary  than  with  dry  mixtures  and  therefore 
the  forms  are  less  likely  to  be  knocked  out  of  position.  With  wet  mixtures 
in  comparatively  thin  walls  two-inch  planking  should  be  supported  not  over 
5  feet  apart,  while  for  one-inch  boards  2  feet  is  about  the  right  spacing. 

Forms  are  greased  by  applying  to  them  a  coat  of  crude  oil  or  soft  soap, 
but  if  the  forms  are  not  to  be  removed  for  several  weeks  no  greasing  is  neces- 
sary, though  in  this  case  the  surfaces  of  the  forms  which  are  to  come  in  contact 
with  the  concrete  must  be  thoroughly  wet. 

25 


PAVEMENT  IN  CITY  OF  PANAMA. 


BRIDGE  NEAR  WASCO,  ILL. 
26 


CHAPTER  II. 

SIDEWALKS,  CURBS,  AND  GUTTERS. 

Concrete  is  in  universal  use  for  sidewalks,  curbs,  and  gutters,  and  the 
excellent  and  permanent  qualities  of  this  material  are  as  well  shown  in  these 
forms  as  in  any  other  type  of  construction  in  which  it  is  used.  Sidewalks 
should  be  smooth,  durable,  cheap  in  first  cost,  and  should  present  a  pleasing 
appearance.  With  proper  care  concrete  can  be  laid  to  satisfy  all  these  require- 
ments and  therefore  make  a  solid  durable  walk.  For  curbs  alone  or  for 
combined  curbs  and  gutters,  especially  for  the  streets  in  residential  districts, 
parks  or  similar  places  where  neatness  of  appearance  is  especially  desirable, 
concrete  is  being  used  in  many  localities  almost  exclusively.  In  this  chapter 
are  shown  methods  of  construction  which  are  standard  and  which  if  followed 
will  produce  good  results. 


FIG.  3—  CROSS  SECTION  OF  SIDEWALK  AND  COMBINED  CURB  AND  GUTTER. 


DIMENSIONS  OF  WALKS,  CURBS,  AND  GUTTERS. 

A  first  class  walk  consists  of  a  foundation  of  cinders,  gravel,  or  broken 
stone  upon  which  is  laid  a  layer  of  concrete  called  the  base  and  an  upper  thin 
layer  of  mortar  called  the  wearing  surface.  Granolithic  is  a  common  name 
for  concrete  walks. 

Sidewalks  vary  in  width  according  to  conditions,  but  the  thickness  of  the 
concrete  is  nearly  uniform,  ranging  from  four  to  five  inches  total  thickness 
including  the  wearing  surface. 

In  Fig.  3  is  shown  the  section  of  a  sidewalk  separated  from  the  curb  by  a 
narrow  grass  plat  such  as  is  common  in  residential  streets.  The  thickness 
of  the  concrete  is  shown  as  5  inches,  but  4  inches  is  more  commonly  used, 
and  if  the  walk  is  provided  with  good  foundations  and  drainage  4  inches  is 
ample  in  most  places.  Where  the  total  thickness  of  the  concrete  is  4  inches 
the  base  should  be  3%  or  3  inches  and  the  wearing  surface  ^4  or  i  inch,  and 
for  a  5-inch  walk  the  base  should  be  4  inches  and  the  wearing  surface  i  inch. 


The  slope  of  the  surface  from  the  lot  line  toward  the  curb  should  be  ^4  or  H 
inch  per  foot.  For  parks  and  similar  locations  the  walk  is  usually  crowned 
toward  the  center. 

Curbs  are  made  from  6  to  8  inches  wide  on  top  and  are  generally  vertical 
on  the  side  next  to  the  walk  and  slightly  inclined  on  the  side  facing  the  gutter. 
The  total  depth  of  the  curb  should  be  from  12  to  14  inches,  and  if  the  street 
traffic  is  heavy  the  curb  should  set  upon  a  concrete  base  12  inches  wide  and  8 
inches  thick.  Where  the  curb  and  gutter  are  combined,  as  shown  in  Fig.  3, 
the  gutter  is  made  8  inches  thick  and  from  1^2  to  3  feet  in  width.  In  the 
case  shown  the  curb  has  a  width  on  top  of  6  inches  and  tapers  down  to  6^ 
inches  at  the  gutter.  Sometimes  both  the  inner  and  outer  surfaces  of  the 
gutter  are  made  vertical,  although  it  is  better  to  have  the  front  face  inclined. 
The  upper  outer  corner  of  the  curb  and  the  intersection  of  gutter  with  face  of 
curb  should  be  rounded  off  with  radii  of  about  i  inch. 

The  surface  of  the  gutter  should  conform  to  that  of  the  street  surface, 
though  in  some  cities,  as  for  instance  Salt  Lake  City,  the  upper  surface  of  the 
gutter  is  curved  in  such  a  manner  as  to  secure  greater  carrying  capacity,  the 
depth  of  the  gutter  being  10  inches,  whereas  it  would  be  only  8  inches  were 
the  curve  omitted  and  the  slope  of  the  street  continued  to  the  curb  line.  At 
street  corners  curbs  should  be  thicker  than  where  straight  so  as  to  better 
withstand  shocks  from  moving  vehicles.  Where  the  street  traffic  is  heavy,  the 
upper  outer  edge  of  the  curb  is  often  provided  with  a  special  steel  .corner 
imbedded  in  the  concrete  as  it  is  laid. 

Fig.  4  illustrates  a  type  of  concrete  curb,  gutter,  and  cross  walk  construc- 
tion used  considerably  in  Chicago  on  streets  for  ordinary  traffic.  A  cross 
walk  is  provided  by  elevating  the  street  surface  near  the  curbs  as  shown. 

FOUNDATIONS    AND    DRAINAGE. 

A  good  foundation  properly  drained  is  absolutely  essential  for  successful 
sidewalk  construction,  and  is  best  made  by  excavating  the  soil  to  a  depth  of 
10  to  15  inches  below  the  level  of  the  finished  sidewalk  surface,  depending  on 
the  kind  of  soil  and  the  locality,  so  as  to  give  a  foundation  6  to  10  inches 
thick,  and  after  ramming  the  bottom  of  the  excavation  a  layer  of  coarse 
material  such  as  broken  stone,  cinders,  or  coarse  sand  is  placed  in  the 
excavation  and  thoroughly  rammed.  Drainage  and  ramming  are  of  the 
utmost  importance.  In  some  cities  no  foundation  is  required  in  soils  of 
clean  coarse  sand  which  is  porous  enough  to  afford  good  drainage,  while 
in  soils  which  retain  water  a  foundation  of  6  to  12  inches  is  specified. 
Fig.  3  shows  an  8-inch  foundation  of  cinders  under  the  walk  and  one  of  10 
inches  under  the  curb  and  gutter.  Broken  stone  or  gravel  should  be  screened 

28 


29 


to  remove  all  fine  material  and  cinders  and  sand  should  be  wet  while  being 
rammed  into  place.  In  soils  like  clay  which  retain  water  the  foundation 
should  be  drained  by  running  occasional  drain  tiles  underneath  the  soil  from 
the  foundation  to  the  gutter,  or  other  suitable  outlet.  Instead  of  tile  drains 
small  ditches,  say  10  by  10  inches  in  cross  section,  filled  with  broken  stone 
may  be  used. 

PROPORTIONS  FOR  CONCRETE. 

Portland  cement  only  should  be  used. 

The  concrete  for  the  base  should  be  mixed  i  part  "ATLAS"  Portland 
Cement,  2^/2  parts  sand  or  fine  stone  which  will  pass  a  ^4-inch  screen,  and  5 
parts  broken  stone  or  gravel  larger  than  *4  mcn  size.  Where  the  quality  of 
the  sand  and  stone  require  it,  these  proportions  must  be  slightly  changed,  and 
if  the  sand  is  not  very  good  i  part  "ATLAS"  Portland  Cement,  2  parts  sand 
and  4  parts  stone  or  gravel  had  better  be  used. 

The  wearing  surface  should  be  mixed  i  part  "ATLAS"  Portland  Cement  to 
i*/2  parts  sand,  and  should  be  of  such  consistency  as  not  to  require  tamping, 
but  should  be  simply  floated  with  a  straight  edge.  The  sand  here  referred 
to  may  be  either  natural  bank  sand  or  crushed  stone  which  will  pass  a  ^-inch 
screen  provided  it  is  from  a  hard  stone  which  has  but  little  dust. 

Another  excellent  plan  is  to  use  i  part  "ATLAS"  Portland  Cement  and  % 
part  sand  and  y$  part  fine  crushed  stone. 

Although  i  part  cement  to  2  parts  fine  aggregate  is  quite  frequently  used 
for  the  wearing  surface  this  mixture  is  liable  to  make  a  surface  that  will  wear 
sandy. 

The  combined  curb  and  gutter  shown  in  Fig.  3  is  laid  on  a  cinder  founda- 
tion and  the  concrete  base  and  i-inch  finish  are  of  the  same  mixtures  as  speci- 
fied for  the  corresponding  parts  of  the  walk. 

FORMS. 

Forms  should  be  made  of  clean  lumber  not  less  than  2  inches  thick,  though 
iY2  may  be  used  if  well  braced.  Fig.  5  shows  typical  form  construction  for 
walks  and  combined  curb  and  gutter.  The  walk  shown  is  5  inches  thick  and 
the  side  forms  are  2  by  6  inches,  although  2  by  5  inches  will  do  if  available. 
The  upper  edge  must  be  the  exact  level  of  the  finished  walk.  The  forms 
should  be  of  best  white  pine  planed  on  all  sides,  should  be  straight  and 
set  to  true  line  and  grade.  If  white  pine  is  too  expensive,  spruce,  fir,  or 
other  soft  woods  may  be  used.  The  wooden  pegs  should  be  spaced  from 
4  to  6  feet  apart  and  must  be  securely  driven  into  the  ground  so  that  the 
forms  will  not  move  while  concrete  is  being  deposited  against  them. 

30 


The  gutter  shown  as  5  inches  thick  in  the  drawing  is  suitable  for  streets 
with  light  traffic.  The  curb  is  6  inches  wide  and  1 1  inches  deep  with  both  faces 
vertical.  The  side  planks  are  held  in  place  by  the  wooden  pegs  and  the  front 
plank  for  the  curb  is  held  by  clamps  and  steel  dividing  plates,  the  latter  serv- 
ing as  spacers  as  well  as  dividing  plates  at  the  joints.  The  upper  corner  of 
the  curb  should  be  rounded  to  a  radius  of  i  inch  with  a  tool  and  the  lower 
corner  at  the  intersection  of  the  gutter  and  curb  should  be  similarly  arranged 
by  rounding  off  the  lower  inner  edge  of  the  front  plank  of  the  curb  form. 


fOf?M5.  \j  \}CQMB/N£&  CWBJA/0   V 

FIG.  5— FORMS  FOR  SIDEWALK  AND  COMBINED  CURB  AND  GUTTER 

PLACING   CONCRETE. 

After  having  placed  and  thoroughly  rammed  the  porous  foundation,  and 
having  carefully  set  the  forms  to  line,  as  described  above,  divide  the  surface 
into  blocks  by  cross  lines.  Mark  the  dividing  lines  between  the  blocks  on  the 
side  forms  by  notches  and  place  cross  strips  from  form  to  form  located  by 
these  notches.  The  blocks  should  be  nearly  square,  and  for  walks  4  inches  in 
thickness  should  not  be  over  6  feet  in  longest  dimension,  while  for  walks  5 
inches  in  thickness  8  feet  is  about  the  maximum  size.  By  laying  alternate 
blocks,  and  then  after  the  concrete  has  stiffened,  removing  the  cross  strips 
and  filling  in  the  blocks  between,  joints  are  made  so  that  if  the  walk  heaves 


FIG.  6.— CINDER  FOUNDATION  FOR^CONCRETE^SIDEWALK. 


FIG.  7.— PLACING  THE  CONCRETE  BASE. 


slightly,  it  will  crack  in  the  joint  and  will  not  show,  provided  of  course  the 
wearing  surface  is  grooved  and  jointed  directly  above  the  joint  in  the  base. 

Mix  the  concrete  for  the  base  on  a  tight  platform  unless  the  street  pave- 
ment is  hard  and  impervious,  in  which  case  that  can  be  used  for  mixing. 
Make  the  consistency  rather  stiff,  but  wet  enough  so  that  the  concrete  will 
glisten  when  it  is  being  mixed,  and  although  holding  its  shape  in  a  pile,  can 
be  compacted  and  the  mortar  brought  to  the  surface  with  comparatively  light 
ramming.  See  that  the  surface  of  the  base  is  exactly  one  inch  below  the  upper 
level  of  the  forms,  so  that  the  wearing  surface  will  be  uniformly  one  inch 
thick.  To  accomplish  this,  make  a  straight-edge  of  ^4  inch  wood  notched  at 
each  end  to  fit  upon  the  forms. 

As  soon  as  a  few  blocks  of  the  base  have  been  laid,  and  before  the  concrete 
has  set,  mix  the  mortar  for  the  wearing  surface.  Make  this  one  part  "ATLAS" 
Portland  Cement  to  one  and  a  half  parts  sand  or  finely  crushed  stone  and  sand 
mixed.  This  mortar  may  be  mixed  in  a  mortar  box,  as  it  has  to  be  of  about 
the  consistency  of  mortar  for  laying  brick. 

To  secure  good  results  and  prevent  the  wearing  surface  from  eventually 
cracking  from  the  base,  it  is  absolutely  essential  that  the  mortar  be  spread 
before  the  concrete  base  has  begun  to  stiffen,  for  if  it  is  left  for  several  hours 
or  over  night  the  wearing  surface  is  almost  sure  to  peal  off  in  places. 

After  smoothing  the  wearing  surface  with  a  straight-edge,  float  it  roughly 
with  a  plasterer's  trowel,  and  after  a  few  hours,  when  the  mortar  has  begun  to 
stiffen,  float  it  with  a  wooden  float,  and  then  with  a  metal  float,  or,  as  it  is 
sometimes  called,  a  plasterer's  trowel.  Neat  cement  should  not  be  applied  to 
the  surface.  Just  as  the  final  floating  is  being  finished,  take  a  small  pointing 
trowel,  and  guided  by  the  notches  in  the  side  forms  and  by  a  straight-edge, 
placed  across  the  walk,  run  the  trowel  down  between  the  blocks  so  as  to  form 
a  joint  in  the  wearing  surface  directly  above  the  joint  in  the  base,  and  finish 
this  joint  with  a  groover,  so  as  to  give  it  rounded  edges.  The  side  edges  of 
the  walk  are  then  rounded  off  with  a  special  jointer,  and  the  surface  again 
finally  troweled. 

If  a  roughened  surface  is  desired,  a  dot  roller  or  a  grooved  roller  may  be 
used.  The  walk  should  be  protected  from  the  sun  for  at  least  four  days,  and 
wet  down  frequently. 

Curbs  and  gutters  should  be  laid  in  advance  of  the  walk  in  sections  5  or  6 
feet  in  length  and  a  joint  should  be  left  between  the  curb  and  the  walk.  The 
surface  of  the  gutter  and  the  top  and  front  surface  of  the  curb  should  be  made 
of  a  i -inch  layer  of  mortar  the  same  as  used  for  the  wearing  surface  of  the 
walk.  It  is  important  to  place  the  upper  part  of  the  curb  at  the  same  time 
with  the  lower  for  the  perfect  union  of  the  two  parts  is  necessary  to  keep  the 
curb  in  position. 

33 


FIG.  8.— MIXING  MORTAR  FOR  WEARING  SURFACE. 


FIG.  9.— TROWELING  WEARING  SURFACE. 
34 


COLORING   MATTER. 

By  selecting  a  crushed  stone  of  the  proper  variety  a  permanent  color  can 
be  secured  for  the  surface  of  a  walk,  some  pink  granites  giving  especially 
pleasing  effects.  Artificial  coloring  matter  may  be  secured  by  the  addition 
of  lamp  black,  ochre,  iron  oxide,  and  other  materials  to  the  cement,  but  most 
of  these  colors  will  fade. 


MATERIALS  FOR  CONCRETE  SIDEWALKS,  FLOORS  AND  WALLS 


of  Cement  to  100  sq.  ft.  of  Surface 
area  of  Concrete  Base  or  of  Wall 


Thick- 
ness, 
Inches 

Proportions 

Thickness, 
Inches 

Proportions 

i 

1:1V2:3 

1:2:4 

1:3:6 

1:1 

1:1H 

1:2 

3 

&A 

6M 

4% 

y* 

3*2 

2% 

2M 

4 

11 

8% 

6 

z/ 

5                      43^ 

5 

14/^ 

11 

7*^ 

1 

7 

6 

16% 

13  M 

91^ 

1% 

8  %                  6^^             5  ^^ 

8 

22% 

18 

12 

1*£ 

10 

8 

6V^ 

10 

28% 

21*^ 

15^ 

1% 

12 

91^ 

7% 

12 

34% 

26^ 

18J^ 

2 

14 

11 

9 

Bags  of  Cement  to   100  sq.  ft.  of  Mortar 
Surface 


No.  of  sq.  ft.  of  Concrete  Laid  with 
4  Bags  (1  bbl.)  of  Cement 

No.  of  sq.  ft.  of  Mortar  Surface  Laid  with 
4  Bags  (1  bbl.)  of  Cement 

Thick- 
ness, 
Inches 

Proportions 

Thickness, 
Inches 

Proportions 

1:1^:3 

1:2:4 

1:3:6 

1:1 

1:1^2 

1:2 

3 
4 
5 
6 
8 
10 
12 

47 
36 
27 
24 
17 
14 
12 

60 
46 
36 
30 
22 
19 
15 

83 
66 
52 
41 
33 
26 
21 

H 

i* 

1M 
1H 

1* 

114 
80 
57 
48 
40 
33 
29 

146 
100 
73 
60 
50 
43 
36 

178 
114 
89 
70 
59 
52 
44 

35 


QUANTITIES   OF   MATERIALS    FOR    SIDEWALKS. 

For  the  computation  of  the  quantities  of  cement,  sand,  and  stone  required 
to  construct  a  sidewalk  of  any  given  dimensions  the  accompanying  table  will 
be  found  useful  as  giving  the  quantities  required  to  lay  100  square  feet  of 
sidewalk.  The  values  given  are  based  on  a  barrel  of  3.8  cubic  feet  and  a 
coarse  aggregate  having  45  per  cent  voids  are  assumed.  In  the  table  allow- 
ances have  been  made  for  waste.  To  determine  the  total  volumes  required 
for  a  walk  of  given  proportions  and  dimensions  the  amounts  noted  for  the 
base  and  for  the  wearing  surface  should  be  added  together.  The  quantities 
required  will  of  course  vary  with  the  proportions  and  character  of  the  ma- 
terials. 


FIG.  10.— CONCRETE  SIDEWALK  IN  SOUTH  BETHLEHEM,  PA. 


COST. 

The  cost  of  sidewalks,  curbs  and  gutters  varies  with  the  locality,  size  of 
the  job,  and  with  the  character  of  the  soil  and  materials  used.  Work  finished 
recently  under  contract  for  Salt  Lake  City  shows  the  following  costs  to  the 
city.  These  figures  are  based  on  a  day's  work  of  eight  hours  and  laborers  at 
$2  per  day,  form  setters  $4  per  day.  Costs  given  below  are  per  linear  foot: 

Concrete  curb,  6  x  16  inches,  without  gutter $0.43 

Concrete  curb,  plain,  6  x  16  inches,  with  gutter  30  inches  wide 0.79 

Concrete  curb,  plain,  6  x  16  inches,  with  gutter  30  inches  wide  and  curved  to  special 

radius  0.85 

Concrete  curb,  6  x  16  inches,  reinforced,  without  gutter  and  curved  to  special 

radius  0.64 

Concrete  gutter,  30  inches  wide  along  curb 0.61 

36 


Mr.  George  W.  Tillson*  gives  the  cost  of  concrete  walks,  5  inches  thick 
and  laid  on  7  inches  of  cinders  in  Brooklyn,  N.  Y.,  as  16%  cents  per  sq.  ft. 

Fig.  10  shows  a  walk  built  of  "ATLAS"  Portland  Cement  in  South  Bethle- 
hem, Pa.,  where  the  current  price  for  walks  similar  to  that  shown  is  from  17  to 
20  cents  per  sq.  ft.  including  curb  and  gutter.  The  walk  is  4  feet  wide,  has  a 
3-inch  base  of  i  :2  14  concrete  and  a  wearing  surface  of  1 12  mortar,  and  is  laid 


L*^.--7*?&F:-.:.    ./  ooncsere 
_!^r_ 


FIG.  11.— CONCRETE  CROSS-WALK  OVER  GUTTER. 

on  an  1 8-inch  cinder  foundation.  The  front  face  of  the  curb  is  4  inches  high 
and  the  gutter  is  14  inches  wide  and  4  inches  thick.  Street  traffic  is  light  so 
that  heavy  curbs  and  gutters  are  not  required  at  this  location. 

Fig.  ii  and  Fig.  12  show  a  small  cross-walk  leading  from  a  front  walk  in  a 
yard  over  a  gutter  to  a  country  road.  The  walk  is  4  feet  in  width  and  the 
total  length  from  house  to  road  is  13%  feet.  The  walk  in  the  yard  is  3  inches 


FIG.  12.— CONCRETE  CROSS-WALK  OVER  GUTTER. 


*"Street  Pavements  and  Paving  Materials/'  p.  479. 

37 


thick,  and  On  each  side  of  the  circular  opening  is  12  inches  thick,  while  under 
the  opening  there  is  a  thickness  of  6  inches.  An  1 8-inch  cinder  foundation 
underlies  the  whole  work.  Two  cement  barrels  were  used  in  place  of  forms 
and  the  total  cost  of  the  walk  and  cross-walk  was  $13.20,  or  24^2  cents  per 
sq.  ft. 

VAULT   LIGHT   CONSTRUCTION. 

In  Fig.  13  is  shown  a  design  for  vault  light  construction  supported  on 


w&m 
» 

WiSr 

§H 


l?4-;<* 

5<!M 

W 

fe 
_iMk; 


FIG.  13.— TYPICAL  VAULT  LIGHT  CONSTRUCTION.* 

concrete  ribs  on  steel  I  beams.  The  sizes  of  the  concrete  ribs  and  the  steel  I 
beams  depend  on  the  spans,  and  it  is  necessary  to  construct  the  concrete  ribs 
and  slab  at  one  time.  The  glass  discs  are  imbedded  in  the  concrete  and  admit 
light  to  the  area  below. 


*See  reference,  footnote,  page  18. 


CHAPTER   III. 

STREET   PAVEMENTS. 

The  ideal  street  pavement  is  durable,  noiseless,  cleanly,  easy  to  travel  on, 
low  in  first  cost,  and  built  of  such  material  that  the  maintenance  charges  are 
small.  Scarcely  any  material  has  been  found  which  entirely  satisfies  these 
requirements,  but  some  of  the  pavements  of  Portland  cement  concrete  which 
have  been  built  in  recent  years,  where  the  concrete  forms  not  only  the  founda- 


HASSAM  PAVEMENT,  PORTLAND,  OREGON. 

tion  but  also  the  wearing  surface,  are  giving  thorough  satisfaction  and  ap- 
proach closely  to  the  ideal  for  streets  where  the  traffic  is  not  so  excessive  as 
to  require  a  stone  block. 

For  pavement  foundations,  concrete  is  used  almost  universally  in  city 
streets  where  the  wearing  surface  is  asphalt,  brick,  wooden  blocks  or  stone 
blocks,  and  there  is  no  material  which  can  be  compared  with  it  for  this  pur- 
pose. Its  use  for  the  wearing  surface  is  comparatively  new,  but  it  is  proving 
its  usefulness  to  a  remarkable  degree. 

Concrete  sidewalks  made  of  a  concrete  base  with  a  granolithic  or  mortar 
wearing  surface  have  been  in  successful  use  ever  since  the  beginning  of  the 
Portland  cement  industry.  As  early  as  1894  alleys  were  paved  with  concrete 
in  Boston,  using  methods  similar  to  sidewalk  construction  except  slightly 

39 


thicker  layers  of  concrete  and  surface  divisions  into  small  blocks  instead  of 
large  ones,  so  as  to  give  better  footing  for  horses. 

Probably  the  first  street  pavement  of  concrete  was  built  in  Richmond, 
Ind.,  in  1903,  on  Sailor  Street,  and  in  1906,  when  it  was  necessary  to  cut  a 
trench  the  entire  length  of  this  pavement  for  telephone  conduits,  the  concrete 
was  found  so  hard  that  it  could  be  cut  only  with  great  difficulty.  On  the 
completion  of  the  conduit  the  pavement  was  repaired,  and  in  1908  it  seemed 
to  be  as  good  as  when  laid  in  1903. 

An  alley  pavement  in  Richmond  adjacent  to  the  Wescott  Hotel,  and  built 


BRIDGE    AT    HAWORTH,  N.  J. 


in  1896,  in  which  a  very  heavy  traffic  is  confined  to  a  small  space,  proved  so 
satisfactory  that  the  street  pavement  was  an  outgrowth  of  it.  An  examina- 
tion of  this  alley  in  1908  showed  the  surface  to  be  in  good  condition  with  very 
little  signs  of  wear. 

Concrete  street  pavements  contain  the  maximum  number  of  desirable 
qualities  as  compared  with  pavements  of  other  materials.  They  are  low  in 
first  cost,  since  the  materials  of  which  they  are  made  are  within  easy  reach 
of  all  localities  desiring  good  pavements.  Practically  no  section  of  the  coun- 
try is  without  stone  or  gravel  good  enough  for  the  main  body  of  the  pavement, 

40 


and  if  local  sand  is  too  poor  in  quality  and  freight  rates  prohibit  importing 
good  sand,  fine  crushed  stone  may  be  used  in  its  place.  "ATLAS"  Portland 
Cement  is  within  the  reach  of  every  section  of  the  country. 

The  quality  of  materials  and  workmanship  for  concrete  pavements  is  of 
greater  importance  than  in  almost  any  other  form  of  concrete  construction. 
The  aggregate  must  be  chosen  with  extreme  care,  the  cement  must  be  of  a 
first-class  standard  brand,  the  proportioning  of  the  materials  must  be  accurate, 
and  the  consistency  right.  Concrete  roadways  require  expert  workmanship 
but  no  more  so  than  the  laying  of  other  forms  of  pavement.  The  methods 
of  laying  and  the  materials  to  employ  are  best  understood  by  reference  to  the 
descriptions  given  in  the  pages  which  follow  of  pavements  which  have  proved 
successful.  Too  great  stress  cannot  be  laid  upon  the  matter  of  a  first-class 
aggregate  for  the  wearing  surface ;  if  this  cannot  be  obtained  concrete  street 
paving  should  not  be  attempted. 

The  maintenance  cost  of  concrete  pavements  is  very  low.  They  are  not 
injured  by  the  elements  or  by  materials  which  attack  some  forms  of  pave- 
ment. The  cost  of  maintenance  of  a  pavement  includes  the  cost  of  keeping  it 
clean  and  concrete  can  be  easily  cleaned  by  flushing  the  street  with  water, 
since  this  does  not  in  the  least  injure  the  quality  of  the  concrete  whereas  with 
some  other  pavements  constant  flushing  is  extremely  injurious. 

The  item  of  smoothness  is  to  a  large  degree  within  the  control  of  the 
builder  of  the  concrete  pavement;  for  the  surface  can  be  made  perfectly 
smooth  or  it  can  be  left  with  any  degree  of  roughness  by  grooving  the  surface 
or  otherwise.  Clearly,  on  a  steep  grade  the  pavement  should  be  left  so  that 
horses  can  get  a  foothold  and  on  curves  so  that  automobiles  will  not  slip. 
Both  of  these  conditions  can  be  met  by  grooving  or  roughening  the  wearing 
surface  of  the  concrete. 

A  wagon  running  over  a  concrete  pavement  makes  less  noise  than  running 
over  a  stone  block  or  other  similar  pavement  having  many  joints.  Another 
advantage  of  these  pavements  is  that  there  are  very  few  places  where  dust 
and  dirt  can  collect. 

Summing  up  then  the  advantages  of  concrete  pavements  it  is  seen  that 
they  offer  very  little  resistance  to  moving  vehicles,  afford  good  foothold  for 
horses  and  prevent  slipping  of  fast  moving  automobiles,  are  clean,  can  easily 
be  kept  free  from  dirt,  and  are  not  very  noisy.  A  pavement  combining  all 
these  desirable  qualities  is  certainly  one  that  should  commend  itself  to  those 
in  charge  of  construction  and  maintenance  of  our  city  streets. 

CONCRETE  STREET  PAVEMENT  FOUNDATIONS. 
Concrete  was  first  used  in  foundations  for  street  pavements  in  New  York 
City  in  1888.     At  the  present  time  nearly  all  cities  require  that  concrete  foun- 
dations shall  be  laid  under  all  classes  of  pavements.     It  is  well  understood 


that  the  success  of  any  pavement  depends  largely  upon  its  foundation.  To 
insure  a  good  foundation  the  subsoil  should  be  properly  shaped  and  graded 
and  then  thoroughly  rolled  with  a  steam  roller  weighing  not  less  than  10  tons. 
When  rolling  the  sub-grade  care  should  be  taken  to  remove  all  timbers  or 
other  matter  which  may  decay  and  leave  space  underneath  the  foundation. 
All  ditches  or  holes  must  be  filled  and  any  soft  material  removed  and  replaced 
by  good,  dry  gravel  or  similar  materials. 

PROPORTIONS  OF  CONCRETE  FOR  STREET  FOUNDATIONS. 

The  proportions  of  materials  for  concrete  to  be  used  in  foundations  for 
pavements  such  as  granite  blocks  or  asphalt  depend  upon  the  local  conditions. 
The  heavier  the  traffic  the  stronger  should  be  the  foundation.  The  propor- 
tions most  common  are  i  part  "ATLAS"  Portland  Cement,  3  parts  sand,  and 
from  5  to  7  parts  broken  stone  or  gravel.  In  most  cases  i  part  "ATLAS" 
Portland  Cement,  3  parts  sand,  and  6  parts  broken  stone  or  gravel  makes  a 
first  class  foundation.  The  thickness  of  foundations  of  Portland  cement  con- 
crete should  be  6  inches.  The  surface  of  the  concrete  should  be  kept  wet  for 
a  few  days. 

One  square  yard  of  concrete  foundation  6  inches  thick  will  require  1/6  of 
a  cubic  yard  of  concrete.  If  the  mixture  is  1 13 :6,  as  previously  specified,  the 
quantity  of  cement,  sand,  and  broken  stone  in  a  square  yard  of  foundation 
can  easily  be  determined  from  the  tables  of  quantities  in  Chapter  I,  page  19, 
by  dividing  the  quantities  given  by  6.  Thus,  for  i  square  yard  of  6-inch 
foundation  made  of  a  1:3:6  mixture  there  will  be  required  0.185  barrels  of 
cement,  0.078  cubic  yards  of  sand,  and  0.157  cubic  yards  of  stone.  These 
figures  are  based  on  average  conditions,  that  is,  45  per  cent  of  voids  in  the 
broken  stone.  Quantities  may  also  be  found  still  more  directly  from  table  in 
Chapter  II,  page  27. 

COST  OF  CONCRETE  FOUNDATIONS  IN  PLACE. 

The  cost  of  concrete  foundations  for  pavements  varies  greatly  with  the 
proportions  used  and  with  the  cost  of  the  materials  and  labor.  The  cost 
ranges  from  75  cents  to  $1.50  per  square  yard  for  the  usual  thickness  of  6 
inches.  The  following  is  an  estimate  for  the  cost  of  i  cubic  yard  of  i  :3 :6 
concrete  in  place  making  6  square  yards  of  finished  foundation.  For  other 
prices  of  materials  and  labor  the  items  may  be  varied  accordingly. 

Portland  Cement,  i.n  barrels,  $2.00 $2.22 

Sand,  0.47  cu.  yd.,  75  cents 0.35 

Broken  Stone,  0.94  cu.  yd.,  $1.75 1.65 

Labor  with  wages  at  20  cents  per  hour 1.15 

Cost  of  i  cubic  yard,  that  is,  6  square  yards  of  foundation  of  1:3:6  concrete 

in   place    $5-37 

Cost  of  i  square  yard  of  6-inch  foundation 0.90 

42 


MIXING   OF   CONCRETE. 

Machine  mixing  gives  a  better  quality  of  concrete  than  hand  mixing,  but 
unless  a  large  area  is  to  be  concreted  and  the  machinery  is  very  carefully 
selected  and  arranged,  hand  mixing  is  apt  to  be  cheaper  and  is  therefore  more 
commonly  used.  For  hand  mixing  a  tight  matched  board  or  metal  platform 
should  be  used,  and  the  methods  should  conform  to  those  outlined  in  Chap- 
ter I.  The  consistency  of  the  concrete  may  be  somewhat  dryer  than  for  rein- 
forced concrete  work,  but  should  be  wet  enough  so  that  the  mortar  will  flush 
the  surface  with  a  very  little  ramming. 


FIG.  14.— CONCRETE  ROAD  AT  FLUSHING,  L.  I.,  N.  Y 

GANG  FOR  HAND  MIXED  CONCRETE. 

To  illustrate  the  arrangement  of  a  gang  in  street  pavement  foundation 
work,  the  following  example  is  taken  from  actual  practice:* 

Gang  for  a  6-inch  foundation  for  a  street  pavement,  where  the  sand  and  cement 
were  made  into  a  mortar  and  spread  on  to  the  stone,  and  where  two  mixing  platforms 
were  used,  one  on  each  side  of  the  street,  with  a  mortar  box  between  them. 
"One  foreman. 

"Two  men  mixing  mortar  in  one  mortar  box. 
"Four  men  shoveling  stone  alternately  into  two  measuring  boxes. 
"Four  men  working  alternately  on  the  two  mixing  platforms,  spreading  mortar 
on  stone,  mixing  concrete,  and  shoveling  to  place. 

"Three  men  leveling  and  ramming  concrete,  and  also  assisting  to  shovel  to  place. 
"One  man  carrying  water  and  doing  other  odd  work. 

"The  total  quantity  of  concrete  in  proportions  1:2:5  laid  per  day  of  ten  hours  aver- 
aged from  40  to  46  batches  or  29  to  33  cubic  yards  per  day  for  the  gang..  The  gang 
was  not  quite  up  to  the  average,  for  under  given  conditions  they  ought  to  have  turned 
out  regularly  34  cubic  yards  per  day  of  ten  hours." 

*See  reference,  footnote,  page  18. 

43 


CONSTRUCTION  OF  FOUNDATIONS. 

The  whole  operation  of  mixing  and  depositing  concrete  in  pavement  foun- 
dations should  be  carried  on  as  quickly  as  is  possible  with  thoroughness. 
Concrete  which  has  been  mixed  and  has  set  or  hardened  to  any  extent  should 
not  be  allowed  to  be  used  in  the  foundation.  Wherever  possible  the  concrete 
should  be  laid  entirely  across  the  street  without  longitudinal  joints.  Boards 
set  to  proper  elevation  and  curved  on  the  upper  edge  to  conform  to  the  cross 
section  of  the  foundation  are  set  across  the  street  and  between  these  forms 
the  concrete  is  laid. 

When  connection  is  to  be  made  with  any  section  which  has  been  previously 
laid  and  which  is  partially  or  wholly  set  the  edge  of  such  section  must  be 
broken  off  so  as  to  be  vertical,  and  must  be  freed  from  dirt  and  properly  wet 
before  fresh  concrete  is  laid  against  it.  No  carting,  wheeling,  walking  or 
bicycle  riding  should  be  allowed  on  the  concrete  until  it  has  hardened. 

The  top  surface  of  all  concrete  foundations  should  be  left  .rough  so  as  to 
better  hold  the  wearing  surface  which  is  placed  upon  it.  Expansion  joints 
may  be  left  at  intervals  not  over  100  feet  lengthwise  of  the  street.  They  can 
be  made  best  by  setting  in  the  concrete  a  i-inch  board  upright  on  its  edge 
across  the  street  from  the  curb  to  curb  and  after  the  concrete  is  sufficiently 
hardened  the  board  is  removed  and  the  space  filled  with  coarse  or  fine  gravel. 
Expansion  joints  are  especially  necessary  near  a  change  in  grade  of  the  street 
where  expansion  from  heat  may  cause  the  pavement  to  buckle  upward. 

CROWNING  OF  ROADWAYS. 

The  finished  surface  of  all  roadways  should  be  higher  at  the  center  than 
at  the  gutters  to  afford  good  drainage.  Although  engineers  do  not  entirely 
agree  as  to  the  proper  amount  of  this  crowning,  practically  all  agree  that  the 
upper  surface  of  the  sub-grade  and  of  the  foundation  should  be  crowned  to 
conform  to  the  upper  finished  surface  of  the  street  pavement.  Crowning  is 
necessary  on  all  streets  and  for  all  materials  and  the  smallest  crown  which 
will  properly  drain  the  street  surface  is  best. 

The  top  of  the  sub-grade  is  always  below  the  surface  of  the  finished  pave- 
ment by  an  amount  equal  to  the  thickness  of  the  pavement  and  its  cushion, 
if  any,  plus  the  thickness  of  the  concrete  foundation. 

In  addition  to  crowning  of  the  surface  the  street  should  have  a  longitudinal 
grade  so  that  water  can  be  carried  off.  This  grade  should  not  be  less  than 
0.3  feet  or  4  inches  in  100  feet  for  hard  materials  such  as  pavements  of  concrete 
or  good  macadam.  Where  the  street  is  level  the  longitudinal  drainage  must 
be  secured  by  giving  a  grade  to  the  gutters  between  catchbasins.  This  neces- 
sitates varying  the  crown  along  the  street. 

44 


For  widths  of  roadways  between  curbs  of  24,  30,  36,  48,  and  60  feet  the 
crown  should  be  3,  4,  5,  6,  and  8  inches  respectively;  the  inches  given  being 
the  difference  in  elevation  of  the  finished  wearing  surface  at  the  center  of  the 
street  and  at  each  curb. 

The  cross  section  of  the  street  surface  is  curved  and  points  on  this  curve 
can  most  easily  be  located  by  driving  stakes  at  the  center  of  the  street,  at 
each  curb  and  at  points  1/3  and  2/3  distant  from  the  center  to  the  curb  on 
either  side.  The  tops  of  these  stakes  can  be  located  in  the  following  manner : 
Stretch  a  string  across  the  street  so  that  it  will  be  level  at  the  proper  eleva- 
tion of  the  upper  finished  surface  of  concrete  foundation  at  the  center  of  the 
roadway.  Compute  the  ordinates  from  the  string  to  the  elevation  of  the 
finished  surface  of  foundation  at  points  1/3  and  2/3  of  the  distance  from  the 
center  toward  each  curb.  The  ordinate  to  be  measured  down  at  the  1-3  point 
nearest  the  center  is  equal  to  1/9  of  the  amount  of  crown  determined  upon 
and  the  ordinate  to  be  measured  down  at  the  2/3  point  from  the  center  is  4/9 
of  the  total  crown.  This  is  illustrated  in  the  accompanying  table.  Thus, 

TABLE  OF  OFFSETS  FOR  CROWNING  STREETS  OF  VARIOUS  WIDTHS. 


Width  of 

Distance  From 

Distance  From 

Roadway  Be-          Crown 

Center  of 

Vertical  Offset         Center  of 

Vertical  Offset 

tween  Curbs 

Roadway 

Roadway 

Feet 

Inches 

Feet 

Inches                    Feet 

Inches 

24 

3 

4 

%                            8 

iVs 

30 

4 

5 

% 

10 

1% 

36 

5 

6 

% 

12 

2% 

48 

6 

8 

% 

16 

2% 

60                         8 

10 

% 

20 

3% 

for  a  roadway  24  feet  wide  having  a  crown  of  3  inches  the  elevation 
of  the  finished  surface  of  foundation  at  points  4  feet  on  either  side  of 
the  center  should  be  1/9  of  3  inches,  that  is,  1/3  inch  below  the  level 
string,  which  corresponds  with  the  elevation  of  the  upper  surface  of 
concrete  foundation  at  the  center.  At  points  8  feet  out  on  either  side  of  the 
center  of  the  roadway  the  elevations  of  the  finished  surface  of  foundation 
should  be  4/9  of  3  inches,  or  i  1/3  inches,  below  the  string.  The  gutter  of 
course  would  be  3  inches  below  the  surface  at  the  center  where  the  crown  is 
3  inches  as  here  assumed.  The  grade  of  the  sidewalk  next  to  the  property 
line  is  frequently  made  the  same  as  the  center  of  the  street. 

Transverse  rows  of  stakes  similar  to  those  just  described  are  placed  every 
10  to  25  feet  apart  lengthwise  of  the  street.  Of  course,  these  stakes  should  be 
driven  in  after  the  sub-grade  is  thoroughly  rolled  and  shaped  so  that  they 
will  be  parallel  to  the  finished  surface  of  street. 

45 


The  curbs  should  always  be  set  to  line  and  grade  before  the  foundation 
for  the  pavement  is  laid. 

FOUNDATIONS  UNDER  STREET  RAILWAY  TRACKS. 

When  a  street  or  a  portion  of  a  street  under  improvement  is  occupied  by 
street  railway  tracks  and  the  tracks  are  removed  during  construction  work, 
the  excavation  of  that  portion  of  the  street  occupied  by  the  tracks  should  be 
made  to  a  depth  of  6  inches  below  the  bottom  and  6  inches  beyond  the  ends 
of  the  ties.  The  remainder  of  the  excavation  must  correspond  in  depth  to 
that  required  for  the  ordinary  pavement.  The  concrete  along  the  track  is 
then  laid  to  a  thickness  of  6  inches  below  the  bottom  of  the  ties.  The  ties 
and  rails  are  set  in  place  upon  this  layer  and  brought  to  true  line  and  grade. 
Additional  concrete  should  be  tamped  under  and  around  the  rails  and  thor- 
oughly grouted  with  a  grout  made  of  i  part  "ATLAS"  Portland  Cement  to 
2  parts  clean,  sharp  sand.  In  case  concrete  beam  construction  is  used,  that  is, 
where  a  rectangular  beam  of  concrete  is  laid  longitudinally  under  each  rail, 
the  excavation  must  conform  to  special  plans  for  the  track  construction. 

For  sheet  asphalt  pavements  the  top  of  the  concrete  foundation  should  be 
parallel  with  and  3  inches  below  the  finished  surface  grade.  For  stone  block 
pavements  to  allow  for  6-inch  block  and  2-inch  sand  cushion  the  top  of  the 
concrete  is  8  inches  below  the  finished  surface  of  the  pavement.  Brick  pave- 
ments are  usually  4  inches  thick  and  are  laid  with  a  2-inch  sand  cushion 
between  the  bottom  of  bricks  and  top  of  concrete  foundation  so  that  the  con- 
crete is  6  inches  below  the  finished  grade. 

CONCRETE    PAVEMENTS. 

The  use  of  concrete  for  the  wearing  surface  of  a  pavement  as  well  as  for 
the  foundation  is  comparatively  recent.  The  examples  of  these  pavements 
already  built  have  proved  so  successful  that  the  increase  in  this  class  of  con- 
struction will  undoubtedly  be  very  rapid.  If,  as  has  been  indicated,  proper 
care  is  used  in  the  selection  of  the  materials  and  in  the  workmanship,  such 
pavements  will  prove  satisfactory  and  durable. 

Concrete  pavements  have  been  successfully  built  by  several  cities  as  de- 
scribed in  the  pages  which  follow,  and  patented  types  of  pavement,  the  Blome 
and  the  Hassam,  have  also  been  laid  in  various  places.  Pavements  built  in 
Richmond,  Ind.,  and  other  cities,  have  been  made  by  similar  methods  to  those 
employed  for  first-class  sidewalk  construction,  using  a  compacted  and  well 
drained  foundation  of  concrete  and  a  mortar  wearing  surface.  The  Blome 
pavement  is  similarly  made  with  a  concrete  foundation  and  a  concrete  wearing 

46 


surface,  using  specially  selected  materials  and  having  the  surface  divided  into 
blocks..  The  Hassam  pavement  usually  consists  of  well  compacted  layers  of 
broken  stone  with  the  voids  filled  with  Portland  cement  grout  and  thoroughly 
rolled. 


FIG.  15.— BLOME  GRANITOID  PAVEMENT,  OHIO  STREET,  CHICAGO. 

ESSENTIALS    OF   A    CONCRETE   PAVEMENT. 

In  order  that  a  concrete  pavement  shall  prove  satisfactory  the  following 
essentials  must  be  adhered  to : 


(1)  Thoroughly  compacted  sub-foundation. 

(2)  Foundation  (unless  the  soil  is  very  porous)   of  porous  materials  rolled  or 

otherwise  compacted. 

(3)  A  base  of  first-class  Portland  cement  concrete. 

(4)  A  wearing  surface  composed  of  a  standard  Portland  cement  and  a  carefully 

selected  aggregate. 

(5)  Expert  and  very  careful  workmanship. 

The  fine  aggregate  for  the  surface  layer  is  of  the  utmost  importance.  Per- 
haps the  best  material  is  crushed  granite  or  crushed  trap  whose  particles  pass 
a  %-inch  sieve  and  which  contains  scarcely  any  dust.  Sand  may  be  used  pro- 

47 


vided  it  is  of  exceptionally  good  quality,  coarse,  clean,  free  from  clay  or  other 
fine  matter,  and  absolutely  free  from  vegetable  loam.  In  natural  sand  the 
percentage  of  dust  passing  a  sieve  having  100  meshes  per  linear  inch  might 
well  be  limited  to  3  per  cent. 

BLOME  CO.  GRANITOID   CONCRETE  PAVEMENT. 

Pavements  made  entirely  of  concrete  are  coming  more  and  more  into  gen- 
eral use  as  the  true  strength  and  worth  of  concrete  is  becoming  better  known 
and  understood.  One  of  the  all-concrete  pavements  is  known  as  the  Blome  Co. 
Patented  Granitoid  Pavement  and  is  laid  under  patents  owned  by  the  Rudolph 
S.  Blome  Company  of  Chicago.  As  previously  stated  the  Blome  Co.  Granitoid 
pavement  consists  of  a  lower  layer  of  concrete  serving  as  a  base  and  an  upper 
thinner  layer  of  richer  concrete  forming  a  wearing  surface ;  the  two  layers  be- 
ing laid  so  as  to  secure  a  perfect  union,  thus  forming  a  monolith.  The  upper 
surface  is  grooved  to  give  a  good  foothold  for  horses. 


Mcrr/ab/e 


/f?  ca^e  of  c/ay 
or  ofoer  fteavy 


FIG.  16.—  STANDARD  SECTION  BLOME  CO.  PATENTED  GRANITOID  PAVEMENT. 

Fig.  1  6  shows  a  standard  section  of  the  Blome  Co.  Granitoid  Pavement.  It 
consists  of  a  5*4-inch  thickness  of  concrete  with  a  ij^-inch  surface  of  a  richer 
concrete,  the  two  layers  being  laid  so  as  to  give  it  thorough  union.  The 
drawing  shows  a  foundation  of  sand,  gravel,  broken  stone  or  cinders  which 
is  necessary  where  the  soil  is  clay  or  hard  pan  or  in  fact  in  any  soil  except  a 
porous  sand  or  gravel.  Expansion  joints,  *4  inch  wide,  are  left  along  the 
gutters  or  curbs. 

The  granitoid  pavement  has  been  laid  in  many  places  and  has  given  very 
good  satisfaction.  It  presents  a  gritty  surface  and  affords  an  excellent  foot- 
hold for  horses.  On  wet  slippery  streets  horses  travel  more  freely  and  easily 
on  the  granitoid  pavement  than  on  other  more  smooth  and  equally  hard  pave- 
ments. Granitoid  has  been  used  successfully  on  8  per  cent  grades  at  Knox- 
ville,  Tennessee;  on  streets  in  Michigan  where  the  temperature  falls  at  times 

48 


to  40  degrees  below  zero;  and  on  streets  in  the  South  where  the  pavement  is 
subjected  to  intense  heat.  Granitoid  pavements  have  demonstrated  that  when 
properly  laid  concrete  is  not  seriously  affected  by  temperature. 

GENERAL   SPECIFICATIONS   FOR   THE   BLOME   COMPANY 
GRANITOID  CONCRETE  BLOCKED  PAVEMENT. 

The  following  general  specifications  have  been  furnished  through  courtesy 
of  the  Rudolph  S.  Blome  Company  of  Chicago. 

PREPARATION  OF  SUB-GRADE.— The  street  shall  be  graded  (excav- 
ated or  filled  as  the  case  may  be)  to  sub-grade,  including  compacting  and 
rolling  by  means  of  a  heavy  steam  roller,  and  all  slopes,  contours  and  other 
shaping  required  in  the  finished  pavement  shall  be  formed  and  provided  for 
in  said  sub-grade,  so  that  the  foundation  and  pavement  hereinafter  specified 
will  be  uniformly  of  the  same  thickness  throughout.  The  contractor  to  use 
extreme  care  to  remove  all  spongy  material  or  other  unsuitable  or  vegetable 
matter  that  may  be  in  the  way  of  making  this  improvement  a  permanent  one. 

The  contractor  will  bid  with  the  strict  understanding  that  he  or  they  must 
use  all  necessary  precautions  in  preparing  the  sub-grade,  so  as  to  support 
the  pavement  permanently,  and  so  that  the  pavement  shall  remain  at  the 
original  grade  for  a  period  of  five  years.  This  clause  shall  not  be  waived  on 
account  of  any  trenches  or  holes  dug  in  the  street  by  any  corporation  or 
private  party,  prior  to  the  laying  of  the  pavement. 

FOUNDATION. — Where  the  natural  soil  is  of  sandy  or  gravelly  nature,  no 
other  foundation  will  be  required,  but  where  the  natural  soil  is  clay,  the  con- 
tractor shall  grade  for  and  provide  a  foundation  of  sand,  gravel,  crushed  stone 
or  other  suitable  material,  and  which  foundation  after  having  been  flooded 
and  compacted,  satisfactory  to  the  engineer,  shall  be  not  less  than  3  inches 
thick. 

MATERIALS. — Samples  of  the  cement  which  is  proposed  to  be  used  in 
the  work  shall  be  submitted  to  the  engineer  in  such  quantities  and  at  such 
time  and  place  as  will  enable  him  to  make  all  required  tests.*  The  engineer 
reserves  the  right  to  reject  without  recourse  any  cement  which  is  not  satis- 
factory, whether  for  reasons  mentioned  in  these  specifications  or  for  any  good 
and  sufficient  cause. 

All  the  cement  to  be  used  must  be  delivered  on  the  work  in  approved 
packages,  bearing  the  name,  brand  or  stamp  of  the  manufacturer.  It  shall  be 
thoroughly  protected  from  the  weather  until  used  in  such  manner  as  may  be 
directed. 

SAND. — All  sand  shall  be  clean,  dry,  free  from  dust,  loam  and  dirt,  of 
sizes  ranging  from  ys  inch  down  to  the  finest,  and  in  such  proportions  that 

*Specifications  for  the  cement  are  also  included. 

49 


the  voids,  as  determined  by  saturation,  shall  not  exceed  33  per  cent  o£  the 
entire  volume,  and  it  shall  weigh  not  less  than  95  pounds  per  cubic  foot.  No 
wind  drifted  sand  shall  be  used. 

CRUSHED  STONE. — All  crushed  stone  used  in  making  the  concrete  shall 
be  of  the  best  quality  of  limestone,  trap  rock  or  granite,  clean,  free  from  dirt, 
broken  so  as  to  measure  not  more  than  i^  inches  and  not  less  than  ^4  inch  in 
any  dimension.  The  stone  when  delivered  on  the  street  shall  be  deposited 
on  flooring  and  kept  clean  until  used. 

GRAVEL. — If  gravel  is  used,  same  to  be  perfectly  clean  gravel,  free  from 
all  loam  and  foreign  substances,  and  the  same  size  as  that  specified  herein  for 
crushed  stone. 

MIXING  AND  LAYING  OF  CONCRETE  AND  FORMATION  OF  THE 
BLOME  COMPANY  GRANITOID  BLOCKING. 

The  concrete  and  blocking  hereinafter  specified  shall  be  constructed  and 
manipulated  according  to  the  Blome  Company  patents  and  processes,  using 
materials  mixed  in  the  proportions  and  laid  as  hereinafter  specified. 

The  pavement  shall  consist  of  5*4  inches  of  concrete,  and  surface  blocking 
i^4  inches,  making  a  total  of  7  inches,  exclusive  of  foundation. 

After  the  sub-grade  and  foundation  have  been  prepared  as  hereinbefore 
specified,  there  shall  be  deposited  concrete  composed  of  i  part  of  Portland 
cement,  3  parts  sand,  and  4  parts  of  crushed  limestone,  trap  rock,  or  clean 
gravel.  These  materials  to  comply  with  the  requirements  hereinbefore  set 
forth  and  shall  be  mixed  by  special  mixing  machine  suitable  for  the  purpose 
to  be  approved  by  the  engineer  and  shall  be  mixed  at  least  five  times  before 
being  removed  from  the  mixer.  The  concrete  shall  be  thoroughly  tamped  in 
place,  and  shall  be  5^4  inches  thick,  uniformly  at  all  points,  after  having  been 
compacted,  shall  be  laid  in  sections  with  expansion  joints,  all  as  per  the  Blome 
Company  patents  and  shall  follow  the  slopes  of  the  finished  pavement  so  that 
the  surface  blocking  is  and  shall  be  uniformly  of  the  same  thickness  at  all 
points. 

SURFACING  MATERIAL. — After  the  concrete  has  been  placed  and 
before  it  has  begun  to  set,  there  shall  be  immediately  deposited  thereon  the 
Granitoid  Blocking  which  shall  be  i^4  inches  in  thickness  to  be  composed  of 
two  parts  of  the  hereinbefore  specified  Portland  cement  and  three  parts  of 
clean,  crushed  granite,  trap  rock,  hard  stone,  crushed  gravel,  crushed  boulders, 
or  other  similarly  hard  materials  shall  be  screened  with  all  the  dust  removed 
therefrom  utilizing  the  following  composition  of  this  material. 

Fifty  per  cent  of  the  granite,  trap  rock,  hard  stone,  crushed  gravel,  crushed 
boulders  or  other  similarly  hard  materials  to  be  what  is  known  as  %-inch  size, 

50 


30  per  cent  of  the  */s-inch  size,  and  20  per  cent  of  the  i-i6-inch  size  with  all 
finer  particles  removed.  These  proportions  of  sizes  are  extremely  essential 
and  must  be  kept  absolutely  accurate  as  in  this  lies  one  of  the  essential  re- 
quirements to  produce  proper  results.  This  material  to  be  mixed  with  cement 
thoroughly  and  after  being  wetted  to  a  proper  consistency  and  deposited  on 
the  concrete  shall  be  worked  into  brick  shapes  of  approximately  4^2  inches  by 
9  inches  with  rectangular  surface  similar  to  paving  blocks,  all  as  per  special 
method  and  utilizing  grooving  apparatus  as  employed  under  the  Blome  Com- 
pany patents.  The  pavement  shall  be  sloped  in  a  manner  as  required  by  the 
City  Engineer. 

Should  there  be  any  part  or  parts  of  this  pavement  when  completed  where 
the  slopes,  contours,  etc.,  have  not  been  carried  out  in  true  manner  then  under 
this  specification  the  contractor  will  be  required  to  take  up  such  part  or  parts 
down  to  the  foundation  and  replace  same  to  the  proper  level  without  expense 
of  any  kind  to  the  city. 

EXPANSION  JOINTS.— The  contractor  for  the  work  above  specified 
shall  also  be  required  to  provide  for  expansion  joints  across  the  pavement  at 
such  locations  as  may  be  necessary,  which  expansion  joints  shall  extend 
through  the  blocking  and  concrete  and  shall  be  filled  with  a  composition 
especially  prepared  for  the  purpose  according  to  the  Blome  Company  patents. 
These  expansion  joints  shall  be  constructed  in  an  extremely  careful  manner 
under  specific  direction  of  the  City  Engineer. 

PATENTS. — All  fees  for  any  patent  invention,  article  or  arrangement  or 
other  apparatus  that  may  be  used  upon  or  in  any  way  connected  with  the  con- 
struction, erection,  or  maintenance  of  the  work  or  any  part  thereof,  embraced! 
in  the  contract  on  these  specifications  shall  be  included  in  the  price  stipulated 
in  the  contract  for  said  work,  and  the  contractor  or  contractors  must  protect 
and  hold  harmless  the  city  against  any  and  all  demands  for  such  fees  or  claims. 

GUARANTY. — Upon  the  completion  of  the  contract,  the  contractor  shall 
furnish  a  satisfactory  surety  company  bond  executed  by  one  of  the  Surety 

Companies  in  good  standing  in  the  State  of  ,  guaranteeing  the 

pavement  mentioned  against  settlements,  upheavals,  disintegration  and  the 
results  of  faulty  workmanship,  and  the  use  of  materials  of  improper  quality 
for  and  during  the  period  of  five  years  from  and  after  the  date  of  completion 
of  the  pavement. 

It  is  to  be  expressly  understood  that  the  above-mentioned  pavement  shall 
satisfactorily  withstand  all  severe  usage  to  which  same  will  be  subjected  dur- 
ing and  for  the  period  named  above. 

BIDDERS'  ATTENTION.— The  attention  of  the  bidders  is  called  to  the 
following  copy*  of  agreement  in  the  offices  of  the  City  Clerk  for  furnishing 

here  given. 


necessary  materials  and  mixtures  for  laying  the  surfacing  material  of  the  con- 
templated pavements  and  for  the  allowance  of  the  uses  of  certain  patented 
processes  owned  and  controlled  by  the  Blome  Company  and  for  the  expert 
advice  which  will  be  furnished,  which  agreement  forms  a  part  of  these  speci- 
fications and  which  must  be  considered  as  a  requirement  by  prospective  bid- 
ders in  the  making  up  of  their  proposals  on  the  contemplated  work. 


FIG.  17.— BLOME  CO.  GRANITOID  PAVEMENT,  KNOXVILLE,  TENN. 

COST  OF  BLOME  CO.  GRANITOID  PAVEMENT. 

The  cost  of  this  pavement  varies  greatly,  depending  upon  location,  quan- 
tity of  work,  costs  of  the  various  materials  and  labor.  The  price  ranges  from 
$1.50  to  $3  per  square  yard,  not  including  excavation  or  grading.  Its  use 
compares  favorably  in  cost  with  brick,  asphalt,  or  creosote  or  wooden  blocks 
on  concrete  foundations. 

In  Knoxville,  Tenn.,  the  same  granitoid  laid  in  accordance  with  methods 
previously  described  cost  $1.88  per  square  yard  in  place,  exclusive  of  the  grad- 
ing, which  varied  from  15  to  20  cents  per  square  yard  of  pavement,  making 
the  total  cost  of  finished  pavement  from  $2.03  to  $2.08  per  square  yard. 

In  New  Haven,  Conn.,  the  Blome  pavement  has  been  laid  at  $2.25  per 
square  yard. 

52 


A  piece  of  granitoid  block  laid  on  48th  Avenue,  Hawthorne,  111.,  in  the 
fall  of  1904,  was  in  very  good  condition  when  examined  in  January,  1909. 
This  pavement  is  7  inches  thick  and  cost  $3  per  square  yard  exclusive  of 
excavation  or  grading. 

HASSAM   PAVEMENT. 

Hassam  pavements  are  laid  in  the  form  of  a  grouted  macadam  street  or  as 
a  granite  block  pavement  on  a  grouted  macadam  foundation.  In  each  case 
the  work  is  done  in  a  manner  peculiar  to  this  type  of  pavement. 


FIG.  18.— HASSAM  PAVEMENT,  BIDDEFORD,  MAINE. 

HASSAM   GROUTED   CONCRETE  PAVEMENT. 

The  Hassam  pavement  as  usually  laid  consists  of  a  properly  compacted 
sub-grade  upon  which  is  placed  a  layer  of  broken  stone  thoroughly  rolled  to 
a  thickness  of  six  inches  and  made  to  conform  to  the  grades  and  contour  of 
the  street.  After  this  stone  has  been  firmly  compacted  by  rolling  and  the 
voids  reduced  to  a  minimum  it  is  grouted  with  a  Portland  cement  grout  made 
of  one  part  cement  and  two  parts  sand.  This  grout  is  poured  upon  the  stone 
until  all  the  voids  are  filled  and  the  grout  flushes  to  the  surface.  The  rolling 
is  continuous  during  the  process  of  grouting.  Upon  this  surface  is  placed 
a  very  thin  layer  of  pea  stone  which  is  spread  over  the  entire  area  of  the  road- 
way, grouted  and  rolled,  the  rolling  to  continue  until  the  grout  flushes  to  the 
surface.  Expansion  joints  are  left  along  the  curbs.  The  data  given  above  was 
taken  from  the  specifications  of  the  Hassam  Paving  Company  who  have  a 
patent  on  this  pavement. . 

53 


Hassam  pavement  has  been  laid  upon  a  grade  of  7  per  cent  in  Biddeford, 
Maine. 

LONG   ISLAND   MOTOR   PARKWAY. 

The  automobile  is  rapidly  changing  the  conditions  governing  the  building 
of  improved  streets  and  highways.  This  is  particularly  noticeable  along  the 
suburban  highways  where  it  is  possible  to  run  automobiles  at  high  speeds. 
Concrete  pavement  seems  to  be  well  adapted  to  meet  the  conditions  imposed 
by  this  particular  class  of  traffic.  An  example  of  the  Hassam  type  of  pave- 


"    :'  *   "    ••  ••'•• 


FIG.  19.— CONSTRUCTION  OF  LONG  ISLAND  MOTOR  PARKWAY. 

ment  for  automobile  traffic  is  the  Long  Island  Motor  Parkway.  The  paved 
portion  of  this  parkway  is  several  miles  in  length  and  "ATLAS"  Portland 
Cement  was  used  throughout. 

The  method  of  construction  was  as  follows:  The  sub-grade  was  shaped 
and  rolled  with  a  lo-ton  roller.  A  2^2-inch  layer  of  broken  stone  i%  to 
2*/2  inches  in  size  was  then  spread  upon  the  sub-grade  and  upon  this  broken 
stone  a  wire  fabric  reinforcement  was  laid  over  the  entire  width  of  the  road- 
way and  the  separate  sheets  overlapped  as  shown  in  the  photograph.  A  layer 


54 


of  broken  stone  was  then  spread  upon  the  fabric  so  as  to  conform  to  the  cross 
section  of  the  roadway  and  to  give  a  pavement  five  inches  in  thickness  after 
rolling. 


/?e//? forced   Concrete   \ 

4-  32^0" 
.r  ..  ^      ..\*" 


/-/a/f  3ec//on  /n  Cat         \     /-/a/f  ^Section  on  /?'// 


\mnforced  Concrete 


/-fa/f \Sec//o/7  /n  Cat        I   hfr/f  3ec/?'o/7  on  rt 


FIG.  20.— TYPICAL  CROSS  SECTION  OF  LONG  ISLAND  MOTOR  PARKWAY. 

After  the  ballast  was  placed  on  the  reinforcement  it  was  thoroughly  rolled 
and  compacted  with  a  lo-ton  roller.  Portland  cement  grout  made  with  one  part 
of  "ATLAS"  Portland  Cement  and  two  parts  sand  was  mixed  in  a  mechanical 
mixer  and  poured  upon  the  surface  of  the  rolled  ballast  until  all  the  voids  were 
filled  and  until  the  grout  flushed  to  the  surface  after  rolling.  The  grout  was 
colored  with  lampblack  to  slightly  darken  the  finished  pavement.  After  the 
grout  had  been  poured  and  rolled  a  thin  layer  of  pea  stone  was  spread,  grouted, 
and  the  surface  again  rolled  as  before. 

The  finished  pavement  was  given  a  rough  surface  by  brooming  so  as  to 
form  very  small  ridges  at  right  angles  to  the  length  of  the  roadway.  Care 
was  taken  to  complete  all  rolling  after  grouting  each  section  before  a  sufficient 
period  of  time  had  elapsed  to  allow  the  cement  to  take  its  initial  set.  Auto- 
mobiles were  allowed  on  the  finished  pavement  ten  days  after  completion. 

This  pavement  was  laid  by  the  Hassam  Paving  Company  of  Worcester, 
Mass.  No  provision  was  made  for  expansion  or  contraction,  but  as  previously 
stated  the  roadway  was  reinforced  with  wire  fabric.  Fig.  20  shows  typical 
sections  of  the  parkway.  The  upper  drawing  represents  construction  where 
the  road  is  straight,  and  the  lower  where  the  road  is  on  a  curve. 


55 


COST   OF  HASSAM   PAVEMENT. 

A  Hassam  pavement  was  completed  in  Watertown,  Mass.,  during  October, 
1908,  at  a  cost  of  $1.85  per  square  yard.  The  pavement  consists  of  a  6-inch 
thickness  of  rolled  broken  stone  grouted  with  one  part  "ATLAS"  Portland 
Cement  and  two  parts  clean,  fine,  sharp  sand.  The  grdut  was  mixed  in  a 
Hassam  grout  mixer.  The  surface  of  broken  stone  after  the  first  grout  was 
placed  was  covered  with  a  pea  grade  of  broken  stone,  and  this  finer  stone  in 
turn  was  covered  with  a  grout  of  the  proportion  of  one  part  "ATLAS"  Port- 
land Cement  and  one  part  sand,  and  rolled  with  a  steam  road  roller  before  the 
first  grout  had  time  to  set. 


FIG.  21.— HASSAM  PAVEMENT,  WATERTOWN,  MASS. 


HASSAM    GRANITE    BLOCK    PAVEMENT. 

River  Street,  in  Troy,  N.  Y.,  is  paved  with  a  Hassam  Granite  Block  Pave- 
ment on  a  Hassam  foundation.  The  foundation  in  this  pavement  consists  of 
a  6-inch  layer  of  broken  stone  grouted  with  one  part  "ATLAS"  Portland 
Cement  and  four  parts  sand.  Grout  was  mixed  in  a  Hassam  grout  mixer,  was 
poured  upon  the  broken  stone  until  all  voids  were  filled  and  the  grout  flushed 

56 


to  surface.  This  foundation  was  rolled  during  the  process  of  grouting  as 
well  as  being  thoroughly  compacted  by  rolling  before  the  grout  was  applied. 

The  pavement  proper  consists  of  granite  paving  blocks  having  dimensions 
4  to  45/2  inches  deep,  3^  to  4^  inches  wide  and  6  to  12  inches  long,  laid  on 
edge  across  the  street  on  a  sand  cushion  1^2  inches  in  thickness  placed  on  the 
Hassam  foundation.  Pea  stone  was  sprinkled  upon  the  surface  of  the  blocks 
and  swept  into  the  joints  with  wire  brooms,  the  pavement  rolled  to  an  even 
surface  or  rammed  when  roller  could  not  be  used,  and  the  surface  was  then 
swept  clean  and  the  joints  filled  with  a  grout  made  of  one  part  "ATLAS" 
Portland  Cement  and  one  part  clean,  sharp  sand.  The  grout  was  spread 
upon  the  paving  and  brushed  into  the  joints,  the  stone  blocks  having  pre- 
viously been  wet  by  sprinkling,  and  the  grout  was  then  broomed  to  a  fine 
smooth  surface.  The  blocks  were  laid  with  joints  not  to  exceed  J^  inch. 

The  sand  cost  $1.25  per  cubic  yard  delivered  upon  the  street  in  bags. 
Crushed  stone  cost  $1.45  per  cubic  yard  delivered.  Day  labor  cost  $1.75  per 
day  of  8  hours.  Contract  price  including  all  materials  and  labor  was  $3  per 
square  yard.  Fig.  22  shows  a  cross  section  of  this  street. 


foundation,  Concrete  6 

ej  vo/ds  f/7/ed  w/tf>  grovf  of 

Af/es  Cemenf  and 
-4  parfe   of 
Crown 


under 

/8"oufs/de  of  r&//s  <7r>d  9  "deep. 
<5/>ou/der  of  Curb  6" 

^/ope  ^~" per  foot 


FIG.  22.— CROSS  SECTION  OF  GRANITE  BLOCK  PAVEMENT  ON  RIVER  STREET,  TROY,  N.  Y. 

CONCRETE  PAVEMENT  IN  RICHMOND,  IND. 

Numerous  streets  and  alleys  have  been  paved  with  concrete  in  Richmond 
as  previously  stated  in  this  chapter.  The  first  concrete  street  pavement  in 
Richmond  was  laid  in  1896  at  a  cost  of  $1.62  per  square  yard,  since  then  the 
cost  has  been  still  further  reduced. 

The  usual  pavements  for  streets  of  ordinary  traffic  in  Richmond  have  a 
concrete  base  5  or  6  inches  thick  with  a  top  wearing  surface  i  or  1^/2  inches 
thick. 


57 


For  such  pavements,  that  is,  those  requiring  a  thickness  of  6  or  7  inches, 
a  foundation  consisting  of  8  inches  of  rubble,  field  cobble  stone,  the  refuse 
from  quarries,  or  coarse  gravel  is  placed.  On  this  layer  is  spread  sufficient 
gravel  to  fill  the  spaces,  and,  after  flooding  and  ramming,  to  make  a  total 
thickness  of  the  foundation  of  10  inches. 

On  this  foundation  5  inches  of  thoroughly  rammed  1 12  15  concrete  is  laid  in 
blocks  10  feet  by  15  feet. 

The  wearing  surface,  i%  inches  in  thickness,  and  composed  of  one  part 
cement  and  two  parts  clean,  coarse  sand;  or  else  of  one  part  cement,  one  part 
sand,  and  one  part  clean,  crushed  stone  screenings,  must  be  placed  on  the 
5-inch  base  before  the  latter  has  set.  This  wearing  surface  is  troweled  down 
to  insure  contact,  then  leveled  off  with  a  straight  edge.  When  hard  enough 
it  is  floated  or  troweled  to  a  smooth,  continuous  surface. 

The  surface  is  finally  pitted  with  a  brass  roller  except  for  marginal  strips 
two  inches  wide  around  the  edges  of  the  blocks.  The  wearing  surface  is  cut 
into  blocks  the  same  size  as  the  base. 

For  streets  having  heavy  traffic  a  concrete  base  is  laid  in  addition  to  the 
regular  pavement  so  that  the  total  thickness  is  the  same  as  a  brick  pavement 
on  a  concrete  foundation  or  about  eleven  inches  total.  These  pavements  are 
constructed  as  follows: 

Where  necessary  an  8-inch  layer  of  gravel  thoroughly  wet  and  consolidated 
is  used  for  sub-drainage  and  upon  this  gravel  foundation  is  placed  a  6-inch 
layer  of  1 13 :6  Portland  cement  concrete.  When  this  concrete  foundation  is 
strong  enough  to  sustain  the  roadway  pavement  it  is  covered  with  a  coating 
of  fine  sand,  raked  off  with  a  flat  board  rake  so  as  to  remove  all  sand  except 
that  which  may  remain  in  low  places  and  voids  in  the  concrete  foundation. 
Upon  this  sand  is  placed  a  thin  layer  of  tar  paper  and  upon  the  paper  a  1 12  15 
concrete  layer  four  inches  thick. 

Upon  the  above  concrete  is  placed  a  wearing  surface  one  inch  in  thickness 
composed  of  one  part  cement,  one  part  clean,  sharp  sand,  and  one  part  clean 
stone  or  granite  screenings,  mixed  with  water  to  form  a  rather  wet  facing 
mixture.  In  some  cases  this  wearing  surface  is  placed  in  two  layers,  each 
one-half  inch  thick,  the  first  to  be  thoroughly  rammed  to  insure  perfect  con- 
tact; the  second  applied  immediately  after  and  troweled  and  worked  over, 
and  made  to  conform  to  the  finished  surface  of  the  street.  When  sufficiently 
hard,  the  surface  is  floated  and  steel  troweled  and  finished  with  a  cork  float. 

CONCRETE  PAVEMENTS  IN  THE  CITY  OF  PANAMA. 

Fig.  23  shows  West  Fifteenth  Street  in  the  city  of  Panama  being  paved 
with  1:2^:5  "ATLAS"  cement  concrete  five  inches  thick;  after  tamping  in 
place  it  is  finished  with  a  straight  edge  and  trowel.  The  surface  is  smooth  but 

58 


not  slippery.  The  concrete,  hand  mixed,  was  placed  with  wheelbarrows. 
Broken  stone  was  obtained  by  crushing  old  cobble  stones.  The  sand  was  ob- 
tained from  Panama  Beach.  In  1906  and  1907  over  two  miles  of  this  pavement 
was  laid  in  the  city  of  Panama  at  a  cost  of  $2  per  square  yard  on  streets  having 
grades  as  high  as  8  per  cent.  It  was  laid  in  alternate  blocks  or  sections  about 
10  feet  long  lengthwise  of  the  street  and  extending  all  of  the  way  or  one-half 
way  across  the  street  between  curbs.  TKe  streets  vary  in  width  from  13  feet 
to  20  feet  between  curb  lines. 


FIG.  23.— CONCRETE  PAVEMENT  IN  THE  CITY  OF  PANAMA. 

GROUTING  STONE  BLOCK  AND  BRICK  PAVEMENTS. 

For  filling  the  joints  in  stone  block  or  brick  pavements  the  cement  grout 
should  be  mixed  one  part  "ATLAS"  Portland  Cement  and  one  part  clean  sand 
with  enough  water  to  make  the  grout  flow  easily.  The  materials  must  be 
thoroughly  mixed  with  hoes  in  a  tight  box  at  the  place  of  using.  As  soon  as 
the  mixing  is  completed  the  grout  must  be  immediately  poured  out  of  the  box 
upon  the  surface  of  the  pavement  and  broomed  into  the  joints  before  the 
cement  sets. 

Every  twenty-five  feet,  measured  lengthwise  of  the  street,  one  or  two 
transverse  joints  should  be  filled  with  tar  to  provide  for  expansion.  The  joint 
next  to  each  curb  should  also  be  filled  with  tar. 

59 


CHAPTER    IV. 
SEWERS,  DRAIN  TILES,  BROOK  LININGS,  CONDUITS. 

SEWERS. 

While  formerly  all  large  sewers  were  built  of  brick  and  the  smaller  ones  of 
vitrified  clay  or  cast-iron  pipe,  in  recent  years  concrete  has  entered  this  field 
of  construction  and  through  a  process  of  expansion  and  adaptation  has  been 


BOX  CULVERT,  AMHERST,  MASS. 

gradually  supplanting  all  of  these  materials.  At  first  its  use  was  limited  to 
foundations  and  the  lower  part  of  side  walls,  then  to  lining  the  inverts  of  brick 
sewers,  and  finally  increasing  experience  and  additional  confidence  has  led  to 
its  use  for  the  construction  of  entire  concrete  sewers  and  also  sewer  pipes. 

The  larger  concrete  sewers,  molded  in  place,  are  practically  monolithic, 
while  the  smaller  ones,  constructed  by  joining  short  lengths  of  concrete  pipes 
together  and  sealing  the  joints,  make  one  continuous  pipe. 

Aside  from  being  generally  cheaper  than  brick,  concrete  sewers  are  more 
permanent  and  water-tight,  have  a  much  smoother  surface  and  therefore  a 
greater  carrying  capacity,  and  are  less  liable  to  damage  and  collapse  through 
excessive  loads,  vibrations  and  unsuitable  foundations. 

60 


CONCRETE  PIPE  SEWERS. 

While  monolithic  sewers  molded  in  place  are  entirely  satisfactory  for  diam- 
eters of  more  than  30  inches,  owing  to  the  difficulty  of  devising  suitable  forms 
they  are  impractical  and  less  economical  for  smaller  diameters.  Concrete 
pipe,  on  the  other  hand,  can  be  made  economically  and  easily  in  sizes  ranging 
from  3  inches  to  36  inches  inside  diameter. 

Concrete  pipes  can  be  made  wherever  gravel,  sand  and  cement  can  be 
brought  together,  and  at  a  cost  considerably  lower  than  cast-iron  pipe  and 
usually  less  than  vitrified  clay.  They  can  be  molded  as  desired  into  sectional 
forms  which  are  more  conducive  to  stability  and  efficiency  than  the  circular 
cross-section  which  is  necessary  with  cast  iron  or  vitrified  clay.  By  giving 
concrete  pipe  a  broad,  flat  level  base,  they  are  made  to  rest  firmly  and  securely 
on  a  continuous,  flat  earth  foundation,  while  to  secure  such  a  bearing  for  a 
circular  pipe  requires  tamping  the  earth  filling  into  the  space  beneath  the  two 
sides  of  the  pipe  and  also  cutting  out  a  depression  in  which  the  bells  can  rest. 

In  localities  where  there  are  great  variations  in  the  amount  of  sewage 
flowing  through  the  pipes  an  oval  form  of  cross  section  is  better  than  a  cir- 
cular one.  For  this  concrete  must  be  used,  since  vitrified  pipe  cannot  be  made 
into  these  forms  on  account  of  the  warping  due  to  burning. 

This  warping  also  prevents  the  finished  section  of  vitrified  pipe  from  being 
truly  circular  so  that  when  these  pipes  are  fitted  together  there  are  rough 
projections  at  many  points  on  the  inside  of  the  pipe  which  tend  to  collect 
solid  matter  in  the  sewage  and  thus  to  reduce  its  carrying  capacity. 

Concrete  pipes  can  be  given  a  tapering  butt  joint,  instead  of  the  bell  and 
spigot  joint  common  for  vitrified  and  cast-iron  pipe,  which  considerably  re- 
duces both  the  cost  of  manufacture  and  of  joining  the  pipe  with  mortar  in 
the  trench. 

That  concrete  pipes  without  reinforcement  possess  sufficient  strength  for 
use  as  sewers  is  shown  in  the  accompanying  table*  which  gives  the  results  of 

TESTS   OF  PLAIN   CONCRETE  SEWER  PIPE  IN  BROOKLYN. 


Kind 

1 
Diameter,      Thickness, 
Inches             Inches 

Age 

Breaking 
Load,  Lb. 
per  Lin.  Ft. 

A 
B 
B 
A 

B 
B 
C 

A 

A 
B 
B 
B 

12 
15 
18 
12 

15 
18 
6 
9 

12 
15 
18 
24 

13/16 
17/16 
1% 
13/16 

1M 
17/16 
15/16 
13/16 

1% 
1% 

1% 

2y8 

.  .32  days 

1,689 
1,800 
1,767 
1,622 

1,617 
1,522 
2,600 
2,011 

1,983 
1,962 
2,022 
1,978 

I 

.  .  33  days 
.  .  29  days 

.  1  month  .... 

.  2  months  .  .  . 
.  1  month  .... 

years  over  3 

.  7  months  .  .  . 
.  1  month  .  .  .  . 

.  .  29  days 

.  .  3  days 
.  .  29  days 

years 

.  .  9  days 
.  .  20  days 
.  .  7  days 
.  .  28  days 

Several 

2  years  .  .  . 
1  year  
2  years  .  .  . 
2  years.  .  .  . 

A,  circular  pipe  with  flat  base.     B,  egg-shape  with  flat  base.     C,  circular  pipe. 


*Part  of  table  from  Engineering  Record,  Vol.  58,  Nov.  21,  1908,  p.  591. 


tests  on  pipes, made 
Brooklyn,  N.  Y. 

The  pipes  which, 
from  6  to  24  inches, 
sand  to  3  parts  trap 
twenty-nine  days  to 
long  while  the  larger 
into  molds,  and  then 


in  the  testing  laboratory  of  the  Bureau  of  Sewers  of 

as  seen  from  the  accompanying  table,  varied  in  diameter 
were  made  of  a  mixture  of  i^  parts  cement  to  i  part 
rock  screenings,  and  were  tested  at  ages  varying  from 
over  two  years.  The  6-inch  pipes  were  made  24  inches 
diameters  were  36  inches  in  length.  They  were  tamped 
subjected  to  heat  to  dry  them  immediatly  after  molding, 


CULVERT,  DUMONT,  N.'J. 


the  forms  being  removed  within  half  an  hour  after  the  work  on  a  length  was 
started. 

In  testing  a  section  of  the  pipe  it  was  laid  on  a  sand  bed  so  that  the  lower 
one-sixth  of  its  circumference  was  in  contact  with  the  sand  and  then  the 
pressure  was  applied  from  the  testing  machine  along  the  upper  surface  of  the 
pipe  until  the  pipe  broke.  In  order  to  secure  an  even  distribution  of  the 
pressure  along  the  length  of  the  pipe,  the  pressure  was  applied  through  a  strip 
of  plaster  of  Paris  one  inch  wide  and  not  over  one-quarter  inch  thick,  held  in 
place  by  strips  of  wood. 

The  accompanying  table  shows  the  sizes  of  the  pipe  in  inches  together 

62 


with  the  thickness  of  the  walls,  the  age,  and  the  breaking  load  in  pounds  pef 
linear  foot.  In  order  to  break  a  1 2-inch  pipe  32  days  old,  for  example,  a  load 
of  1,689  pounds  on  each  foot  of  length  of  the  pipe  was  required,  the  total  load 
for  the  3  feet  of  pipe  being  thus  three  times  1,689,  or  5,067  pounds. 

The  pipes,  it  must  be  remembered,  were  of  plain  concrete  without  rein- 
forcement. 

LARGE   CONCRETE   SEWERS. 

Large  sewers  and  conduits  are  built  of  plain  concrete  and  also  of  reinforced 
concrete.  For  diameters  of  3  to  4  feet  the  thickness  required  for  good  con- 
struction is  usually  sufficient  without  reinforcement  as  they  can  be  reckoned 
as  strong  as  a  brick  sewer  of  the  same  diameter  which  is  half  again  as  thick. 
For  large  diameter,  reinforcement  is  generally  advisable,  and  the  saving  in 
material  will  more  than  counterbalance  the  added  cost  of  reinforcing.  The 
reinforcement  adds  to  the  strength  of  the  sewer  during  construction,  and  when 
completed  enables  it  to  withstand  a  larger  pressure  after  the  earth  is  filled 
in  around  and  on  top  of  the  pipe,  and  also  renders  it  less  liable  to  damage 
where  there  is  danger  of  settlement. 

THICKNESS  OF  CONDUITS* 


Diameter  of 
Conduit 

Thickness  of 
Crown,  Inches 

Thickness  of 
Haunch,  Inches 

Thickness  of 
Invert,  Inches 

2 
6 
12 

4 

7 
13 

6 
18 
23 

5 
8 

14 

"If  reinforcement  is  used,  the  thickness  for  conduits  for  ordinary  sizes  is  usually  determined  by  the  minimum 

lickness  of  concrete  which  c      '     '  !J  ~'-' *"  ""  f—  *•—*-- 

where  steel  is  advisable  may 


thickness  of  concrete  which  can  be  laid  so  as  to  properly  imbed  the  metal.     This  minimum  for  the  large  diameters 
sel  is  advisable  may  be  taken  as  6  inches." 


As  a  guide  for  determining  the  thickness  of  concrete  required  for  both 
plain  and  reinforced  concrete  sewers,  the  general  rule  used  by  Mr.  William  B. 
Fuller*  is  given  as  follows: 

"If  concrete  is  not  reinforced  and  ground  is  good — able  to  stand  without  sheeting — 
make  crown  thickness  a  minimum  of  4  inches,  and  then  one  inch  thicker  than  diameter 
of  sewer  in  feet.  Make  thickness  of  invert  same  as  crown  plus  one  inch  except  never 
less  than  5  inches..  Make  thickness  at  haunches  two  and  a  half  times  thickness  of 
crown,  but  never  less  than  6  inches..  If  ground  is  soft  or  trench  is  unusually  deep, 
these  thicknesses  must  be  increased  according  to  experienced  judgment." 

SIZES  OF  CIRCULAR  CONCRETE  SEWER  PIPE. 
Fig.  24  shows  one  form  of  concrete  circular  pipes  suitable  for  sewer  con- 


*See  reference,  footnote,  page  18. 

63 


struction.  The  pipes  are  shown  2  feet  6  inches  in  length  over  all,  the  inside 
diameters  can  be  anything  from  12  to  48  inches,  and  the  thickness  of  the  pipe 
from  2  to  6  inches.  The  joints  are  beveled  so  that  when  laid  with  Portland 
cement  mortar  the  joints  will  be  practically  water  tight,  and  will  present  a 
smooth  surface  so  that  solid  matter  will  not  be  deposited,  as  is  apt  to  be  the 
case  in  vitrified  pipe  sewers. 

In  laying  these  pipes  a  little  mortar  mixed  i  part  "ATLAS"  Portland 
cement  and  2  parts  clean  sharp  sand  is  placed  inside  of  the  pipe  in  the  inner 
beveled  surface.  The  pipe  is  then  pushed  hard  against  the  beveled  end  of  the 
length  of  pipe  already  laid,  and  the  motar  smoothed  off  inside  and  outside  of 
the  pipe  so  as  to  make  a  smooth  joint. 


FIG.  24.— LONGITUDINAL  SECTION  OF  SEWER  PIPES. 

The  inside  diameter  of  the  pipes,  D  in  Fig.  24,  are  12,  18,  24,  30,  36,  42, 
and  48  inches,  and  the  thickness  T  in  the  figure  corresponding  to  these  dia- 
meters should  be  2,  3,  4^,  4^,  4^4,  534,  and  6  inches.  That  is,  for  a  12-inch 
pipe  the  thickness  should  be  2  inches;  for  an  1 8-inch  pipe,  3  inches,  and  so  on. 
For  drain  tile,  which  need  not  be  so  thick  as  sewer  pipe,  thinner  pipe  may  be 
used. 


PROPORTIONS  OF  CONCRETE  FOR  SEWER  PIPE. 

Concrete  used  in  the  construction  of  sewer  pipe,  that  is,  in  the  construction 
of  pipes  having  diameters  of  12  or  more  inches,  should  be  mixed  in  the  propor- 
tions of  i  part  "ATLAS"  Portland  Cement,  2  parts  clean,  sharp  sand,  to 
4  parts  crushed  stone  or  clean  coarse  gravel  not  more  than  i  inch  in  diameter. 


CONCRETE  DRAIN  TILE.* 

Tiles  are  used  for  draining  roadways  and  farms.*  A  roadway  of  even  the 
best  material  needs  some  drainage  and  for  roadways  made  of  poor  materials 
drainage  is  absolutely  essential.  Concrete  drain  tiles  are  the  best  for  the  under 
drainage  of  any  roadway  or  sidewalk.  Oftentimes  in  the  construction  of  roads 
and  sidewalks  one  or  more  longitudinal  lines  of  drain  pipes  are  laid  underneath 
the  surface  of  the  road  or  sidewalk  and  at  convenient  places  are  carried  to 
proper  outlets.  Frequently  a  drain  4  inches  in  diameter  is  sufficient  for  drain- 
ing sidewalks  or  roadways. 

SIZE  OF  CONCRETE  DRAIN  TILES. 

Concrete  drain  tiles  are  made  in  sizes  of  4  inches  to  30  inches  inside  dia- 
meter. Ordinarily  the  sizes  from  4  to  12  inches  are  molded  by  machine,  al- 
though they  may  be  made  in  simply  constructed  molds  as  described  in  "Con- 
crete Construction  about  the  Home  and  on  the  Farm,"  while  the  larger  sizes 
are  usually  made  by  hand.  Although  concrete  sewer  pipes  have  either  bell 
shaped  or  other  similar  joints,  concrete  drain  tiles  are  nearly  always  made 
with  plain  ends. 

The  thickness  of  the  shell  for  tiles  varies  from  i  inch  or  even  thinner  for 
the  4-inch  pipes  to  3  inches  for  the  36-inch  pipes.  The  sizes  under  10  inches 
in  diameter  are  made  i  inch  or  less  in  thickness;  the  12  to  24-inch,  from  i  to  2 
inches  thick;  the  24  to  36-inch,  3  inches. 

Usually  sizes  under  10  inches  in  diameter  are  made  18  inches  long  and  those 
10  inches  or  more  are  made  2  feet  long. 

^MIXTURES  FOR  TILES. 

The  best  mixture  for  tiles  is  i  part  "ATLAS"  Portland  Cement  to  3  parts 
clean  coarse  sand,  or  sand  and  gravel  passing  a  ^2-inch  screen. 

A  1 13  mixture  for  drain  tiles  to  be  used  in  roads,  either  for  longitudinal  or 
cross  drains,  gives  the  proper  strength  to  the  pipes.  For  farm  drainage  and 
other  similar  locations  where  there  is  not  much  pressure  exerted  upon  the  pipe 
a  i  :4  mixture  is  sometimes  used. 

CURING. 

For  ordinary  drain  tiles  the  concrete  should  be  mixed  with  enough  water 
so  that  the  moisture  will  show  at  the  surface  when  the  concrete  is  tamped.  As 
a  general  thing,  the  molds  can  be  removed  as  soon  as  the  concrete  is  thor- 


*See  also  "Concrete  Construction  about  the  Home  and  on  the  Farm,"  p.  91.     This 
book  may  be  obtained  by  writing  to  The  Atlas  Portland  Cement  Co.,  New  York. 

65 


oughly  rammed  into  them.  After  the  molds  are  removed,  the  tiles  should  be 
placed  in  the  shade,  and  wet  down  as  soon  as  the  concrete  will  stand  the  water 
without  washing,  which  is  ordinarily  from  8  to  10  hours  after  molding.  It  is 
of  the  utmost  importance  that  they  should  not  be  allowed  to  dry  out  for  at 
least  4  days,  and  they  should  also  be  kept  in  the  shade  for  8  o£  10  days,  being 
wet  once  or  twice  each  day  during  this  period.  If  the  weather  is  very  dry  or 
hot,  3  or  4  wettings  for  the  first  few  days  are  desirable.  A  pretty  good  rule  to 
follow  is  that  the  pipes  must  not  be  allowed  to  dry  "white"  until  they  are  at 
least  8  days  old.  After  this  treatment  the  tiles  should  be  stored  in  an  open 


FIG.  25.— CONCRETE  BROOK  LINING  IN  NEWTON,  MASS. 

yard  to  season  and  harden.    In  ordinary  weather  the  pipes  are  ready  for  ship- 
ment in  30  days. 

LAYING  DRAIN  TILES. 

Concrete  drain  tiles  under  roads  must  have  at  least  i  foot  of  earth  on  the 
top  of  the  pipe  and  they  must  be  laid  on  a  grade  of  at  least  i  foot  in  100  feet, 
that  is,  one  foot  fall  of  the  pipe  in  100  feet  of  distance. 

The  pipes  should  be  laid  with  open  joints,  that  is,  with  the  ends  simply 
abutting  without  any  mortar. 

66 


BROOK  LININGS. 

A  small  stream  of  water  running  through  a  town  or  through  the  flats  ad- 
joining a  town  often  is  the  cause  of  a  great  deal  of  trouble.  If  the  adjoining 
lands  are  to  be  divided  into  house  lots  the  brook  must  be  properly  taken  care 
of.  Usually  the  best  solution  for  this  problem  is  to  change  the  course  of 
the  brook  so  that  it  will  flow  under  a  street  through  a  concrete  conduit.  If 
the  stream  is  not  within  the  limits  of  a  street  the  banks  can  be  lined  with 


rods  spaced '  /O" 


FIG.  26.— CONCRETE  BROOK  LINING  IN  NEWTON,  MASS. 

concrete,  the  top  thus  being  left  open.  The  concrete  lining  prevents  the 
nuisance  caused  by  the  breeding  of  mosquitoes  and  other  insects  along  the 
edges  of  the  open  brook.  Fig.  26  shows  typical  drawings  of  a  brook  lining  in 
Newton,  Massachusetts.  The  concrete  lining,  throughout  most  of  the  length 
is  curved  to  a  radius  of  18  inches,  inside  diameter,  and  for  the  most  part  is 
8  inches  in  thickness,  the  invert  being  8  inches  and  the  thickness  at  the  upper 

67 


surface  of  the  concrete  being  14  inches.  Under  the  ordinary  flow  the  concrete 
channel  does  not  run  full.  During  extreme  high  water  the  cross  section  of 
the  channel  is  not  sufficient  to  carry  the  entire  flow  so  that  once  in  a  great 
while  the  water  overflows  the  normal  cross  section. 

Fig.  26  shows,  in  addition  to  the  normal  cross  section  of  the  channel,  the 
sections  where  it  enlarges  to  pass  under  a  small  culvert  which  carries  a  street 
over  the  brook.  At  section  A-A  the  concrete  is  reinforced  with  half-inch  rods 
spaced  10  inches  apart.  The  culvert  itself  has  a  clear  span  of  8  feet  and  a 
total  depth  of  5  feet.  The  thickness  of  the  invert  of  the  culvert  is  6  inches  at 
the  middle,  gradually  enlarging  towards  the  abutments  while  the  arch  is  7 
inches  thick  at  the  crown  and  increases  gradually  towards  the  abutments  and 
is  reinforced  with  %-inch  steel  rods  8  inches  apart  on  centers. 


"  fw/j/etf  J/ee/ 


fw/s/ed  jfee/ 
/2' 


FIG.  27.—  TYPICAL  CROSS  SECTION,  JERSEY  CITY  CONDUIT; 


The 


Fig.  25  is  an  illustration  of  the  brook  shown  in  detail  in  Fig.  26. 
photograph  was  taken  at  a  very  low  stage  of  the  water. 

For  brook  linings  the  concrete  should  be  mixed  i  part  "ATLAS"  Portland 
Cement,  2^/2  parts  sand  and  5  parts  broken  stone  or  screened  gravel.  Concrete 
linings  should  be  laid  in  sections  not  over  20  feet  in  length,  and  the  end  of 
one  section  should  be  built  into  the  adjacent  section  in  a  tongued  and  grooved 
manner. 

Sometimes  these  concrete  brook  linings  are  connected  with  nearby  sewers 


68 


so  that  the  sewers  are  automatically  or  continuously  flushed  by  some  water 
passing  from  the  brook  into  the  sewer. 

CONDUITS. 

Oftentimes  a  covered  conduit  is  necessary  to  carry  the  water  of  a  brook 
located  under  a  street  surface.  Such  conduits  may  be  made  rectangular  or 
circular  in  cross  section.  They  are  also  frequently  used  for  water  supply 
lines  where  there  is  little  or  no  pressure  within  the  concrete  conduit. 


FIG.  28— JERSEY  CITY  CONDUIT. 

Fig.  27  shows  a  typical  cross  section  and  Fig.  28  a  photograph  of  a  con- 
crete conduit  of  the  Jersey  City  Water  Supply  Company  built  to  carry  a  water 
supply.  This  conduit  is  approximately  8  feet  6  inches  inside  diameter  and  for 
a  length  of  about  20,000  feet  is  made  of  concrete.  About  30,000  barrels  of 
"ATLAS"  Portland  Cement  were  used  in  this  conduit. 

The  thickness  of  the  conduit  at  the  crown  varies  from  5  to  8  inches  de- 
pending on  the  kind  of  material  in  which  the  pipe  is  placed  and  the  depth  of 
the  filling  over  the  pipe.  The  section  shown  in  Fig.  27  is  typical  of  those  used 
in  soft  earth. 

For  sections  laid  in  open  trench  the  concrete  was  mixed  i  part  "ATLAS" 
Portland  Cement  and  7  parts  sand  and  ballast.  The  ballast  was  broken  trap 
rock,  the  run  of  the  crusher  being  used.  All  concrete  was  machine  mixed 
and  was  very  wet. 

69 


CHAPTER   V. 

CULVERTS. 

Concrete  is  an  excellent  material  for  the  construction  of  culverts  as  is 
shown  by  the  great  number  of  concrete  culverts  now  being  built  for  highways 
and  railways.  As  the  entire  culvert  is  made  of  concrete  there  is  nothing  to 
decay  and  the  excessive  maintenance  charges  in  timber  construction  are  en- 
tirely lacking. 

Culverts  vary  greatly  in  size  and  shape.    The  best  way  to  determine  the 


BEAM  BRIDGE  NEAR  PARIS,  MO. 

required  size  for  an  opening  so  that  the  waterway  will  be  sufficient  is  to 
measure  the  width  and  depth  of  the  stream  at  some  narrow  point  near  by 
during  the  high  water  stage,  and  if  possible  compare  this  size  with  that  of 
culverts  over  the  same  stream  in  the  neighborhood.  With  this  information 
the  width  and  depth  of  the  culvert  opening  may  be  chosen. 

Culverts  may  be  either  square,  rectangular,  circular,  or  arched  in  cross 
section.  Generally  the  rectangular  section  is  best  because  it  conforms  more 
nearly  to  the  cross  section  of  the  water  way  and  is  cheaply  and  easily  built. 
Where  the  appearance  is  of  more  importance  than  the  cost,  arch  culverts  are 
preferable  to  other  styles.  Whatever  the  form  of  cross  section  the  construc- 

70 


Reinforcement 


t      rS5 


_ 
End  E7ev0f/on 

6Toor  Box  CUL  VFRT 


FIG.  29.— REINFORCED  CONCRETE  BOX  CULVERTS. 
71 


tion  should  be  such  as  to  prevent  undermining,  that  is,  to  prevent  the  water 
from  running  along  the  outside  of  the  culvert  and  thus  washing  out  the  earth 
embankment. 

Culverts  with  square  or  rectangular  openings  are  called  box  culverts,  and 
those  with  circular  sections  are  called  pipe  or  circular  culverts.  Pipe  culverts 
are  made  entirely  of  concrete  or  else  of  tile  or  iron  pipe  with  a  concrete  head 
wall  at  each  end  of  the  pipe  where  it  projects  from  the  sides  of  the  road. 


BEAM  BRIDGE. 

Concrete  for  culverts  should  be  made  one  part  "ATLAS"  Portland  Cement, 
two  and  a  half  parts  sand,  and  five  parts  broken  stone. 

BOX    CULVERTS. 

Box  culverts  may  have  square  or  rectangular  sections  as  in  Fig.  29  or 
Fig.  32  or  a  section  similar  to  that  shown  in  Fig.  30.  For  small  culverts,  the 
last  is  a  neat  design,  having  an  arch  effect  and  yet  being  cheaply  and  easily 
constructed.  The  cost  of  the  small  box  culvert  shown  in  Fig.  30  may  be 
slightly  reduced  if  the  cross  section  is  made  square,  omitting  the  bevels  at  the 
upper  corners. 

Fig.  29  shows  a  good  design  for  a  4-foot  box  culvert  of  ample  strength  to 
carry  a  highway..  To  prevent  undermining,  a  concrete  invert  or  bottom  is 
used  and  a  baffle  wall  and  apron  at  each  end  should  be  constructed  as  shown 

73 


although  some  culverts  where  the  soil  is  hard  do  not  need  the  apron,  baffle 
wall  or  bottom.  Cobble  stones  or  paving  bricks  may  be  used  instead  of 
concrete  for  covering  the  bottom  between  the  side  walls.  They  may  be  laid 
even  in  running  water  and  in  case  a  dry  season  should  occur  the  spaces  be- 
tween the  stones  or  bricks  may  be  filled  with  cement  grout..  Concrete  must 
not  be  laid  in  running  water  for  the  cement  will  be  washed  out  from  the 
aggregate.  This  4-foot  box  culvert  has  top,  bottom  and  sides  8  inches  in 
thickness  and  is  reinforced  with  expanded  metal  No.  10  gage  having  3-inch 
meshes,  or  with  other  similar  reinforcement  placed  not  less  than  1^2  and  not 
more  than  2  inches  from  the  inner  surface  of  the  culvert.  The  sheet  rein- 
forcement should  also  be  placed  in  the  apron  and  in  the  wing  walls. 

The  lower  part  of  Fig.  29  shows  a  design  for  a  box  culvert  with  opening 
6  by  6  feet  similar  to  the  4-foot  box  culvert  above  described  except  that  round 
steel  rods  are  used  instead  of  sheet  reinforcement.  In  the  bottom  of  the  cul- 
vert proper  the  rods  running  at  right  angles  to  the  length  of  the  culvert  should 
be  H  mcn  m  diameter  and  spaced  5  inches  apart.  For  the  top  they  should 
be  5/8  inch  in  diameter,  spaced  5  inches  apart  and  alternate  rods  should  be 
bent,  as  shown  in  Fig.  29,  to  reinforce  the  side  walls  extending  within  three 
inches  of  the  bottom  surface  of  the  concrete.  This  bending  of  the  alternate 
rods  in  the  top  results  in  the  vertical  rods  of  the  sides  being  spaced  10  inches 
apart.  In  the  apron  the  s/£-inch  rods  should  be  spaced  5  inches  apart  and! 
should  be  bent  up  alternately  so  that  the  vertical  rods  in  the  wing  walls  are 
spaced  10  inches. 

In  addition  to  the  rods  above  mentioned  there  should  be  a  set  of  ^-inch 
diameter  rods  running  parallel  to  the  length  of  the  culvert  spaced  10  inches 
apart  which  should  extend  into  the  apron  and  wing  walls  at  each  end. 

Fig.  31  and  Fig.  32  show  a  reinforced  box  culvert  built  in  Lenox,  Massa- 
chusetts, in  1896,  for  the  Massachusetts  Highway  Commission.  The  body  of 
the  culvert  is  reinforced  with  7/s-inch  square  twisted  steel  rods  8  inches  c.  to  c. 
at  each  corner  where  the  side  walls  meet  the  top  and  bottom,  those  at  the 
bottom  corners  being  24  inches  long  and  bent,  while  those  at  the  top  corners 
are  straight  and  14  inches  in  length.  Four  counterforts  for  bracing  the  side 
walls  are  shown  in  the  plan  and  also  in  section  CiC,  Fig.  32,  are  used  in  this 
culvert. 

Forty  cubic  yards  of  broken  stone,  16  cubic  yards  of  sand,  55  barrels  of 
cement,  and  778  pounds  of  steel  were  used..  One  hundred  twenty-one  cubic 
yards  of  earth  were  excavated.  The  concrete  mixture  was  about  one  part 
"ATLAS"  Portland  Cement,  two  and  one-half  parts  sand,  and  five  parts 
crushed  stone,  and  the  44  cubic  yards  in  the  structure  cost  $660,  or  $15  per 
cubic  yard.  The  earth  excavation  cost  75  cents  per  cubic  yard.  The  total  cost 
of  the  culvert  to  the  Commission,  exclusive  of  the  macadam  roadway  was 

74 


$809.67.  The  cement  cost  the  contractor  $1.85  per  barrel,  plus  50  cents  for 
hauling,  making  the  price  at  the  culvert  $2.35  per  barrel.  The  contractor  paid 
$2  per  load  of  about  i  cubic  yard  for  the  sand  delivered  at  the  culvert  and1 
about  $1.15  per  cubic  yard  for  the  stone.  About  3^2  or  4  days  were  required 
for  excavating  and  the  concreting  extended  over  24  days  including  delays. 

A  small  box  culvert  with  an  opening  2  by  2  feet  is  shown  in  Fig.  30  in 
which  the  head  wall,  culvert  proper,  and  arrangement  of  forms  are  all  clearly 
illustrated.  If  the  soil  is  compact  material  like  hard  clay,  where  the  excava- 
tion can  be  made  to  the  exact  size  and  shape  of  the  culvert,  the  outer  forms 
may  be  omitted,  the  concrete  being  deposited  directly  on  the  bottom  of  the 


FIG.  31.— REINFORCED  CONCRETE  BOX  CULVERT  AT  LENOX,  MASSACHUSETTS. 

trench  to  form  the  invert  of  the  culvert,  then  the  inner  form  set  in  place  and 
the  concrete  deposited  between  it  and  the  walls  of  the  trench. 

The  inner  forms  consist  of  frames  made  of  three  pieces  of  2  by  4  inch  and 
one  piece  of  2  by  6-inch  joists,  notched  as  shown.  Around  these  frames  boards 
are  set.  The  upper  2  by  6  piece  is  not  nailed  so  that  in  removing  the  inner 
forms  after  the  concrete  has  hardened  this  upper  piece  is  first  knocked  out  and 
then  the  2  by  4-inch  pieces  and  finally  the  boards. 

Another  type  of  small  culvert  and  form  as  used  by  the  Iowa  State  High- 
way Commission  is  shown  in  Fig.  33. 

75 


CIRCULAR   OR   PIPE   CULVERTS. 

Circular  or  pipe  culverts  are  made  of  concrete  as  in  Fig.  34,  or  of  metal 
with  concrete  head  walls  as  in  Fig.  35.  The  concrete  culvert  shown  is  3  feet 
in  diameter  and  is  not  reinforced.  An  apron  with  a  baffle  wall  on  each  side  as 
well  as  on  the  outer  end  is  provided  to  prevent  the  water  from  running  along 
the  outside  of  the  culvert  and  thus  washing  out  the  earth. 


Long/fud/na/  -Section 


36  /A/C/J  C/ftCUL/tR 


FIG.  34.— CONCRETE  CIRCULAR  CULVERT. 


Pipe  culverts  are  made  of  cast  iron  or  sheet  iron  or  of  tiles.  They  should 
have  fall  enough  so  that  water  will  not  stand  in  them,  a  slope  of  ^4  inch  per 
foot  being  generally  sufficient.  They  should  also  have  at  least  12  to  18  inches 
of  earth  over  the  top  of  the  pipe  and  the  earth  should  be  thoroughly;  com- 
pacted around  the  outside  of  the  pipe. 

To  prevent  undermining,  head  walls  should  always  be  used  with  pipe  cul- 
verts. In  Fig.  35  head  walls  for  four  sizes  of  metal  pipes  are  shown  and  they 
are  all  similar  except  that  for  the  24-inch  pipe  the  head  wall  has  a  coping 
6  inches  deep  projecting  2  inches  from  the  face  of  the  wall,  and  the  head  wall 
for  the  3-foot  pipe  has  a  concrete  apron  6  by  24  by  48  inches  in  size.  This 
apron  should  slope  up  at  the  inlet  and  down  at  the  outlet. 

78 


The  number  of  cubic  yards  of  concrete  in  one  head  wall  for  the  12,  18,  24, 
and  36-inch  pipe  is  0.64,  1.04,  1.47,  2.57  respectively.  The  2.57  cubic  yards  in 
the  headwall  for  the  36-inch  pipe  includes  the  concrete  in  one  apron. 

If  the  proportions  are  one  part  "ATLAS"  Portland  Cement,  two  and  one- 
half  parts  sand  and  five  parts  broken  stone  or  screened  gravel,  i  1/3  bbls.  ce- 
ment (each  barrel  being  the  same  as  four  bags)  will  be  required  for  a  cubic 
yard  together  with  about  ^  cubic  yard  of  sand  and  a  cubic  yard  of  broken 
stone  or  screened  gravel. 


Section 

WALL  FOP  /&£*//?£ 
9*0- 


E/e"af/on  Sect/on 

HEAD  WALL  rof?  24"P/P£ 


of  face  of  Wa//        Ject/on 


HEAD  WALL 

FIG.  35.^CONCRETE  HEAD  WALLS  FOR  METAL  CULVERTS. 


ARCH  CULVERTS. 

As  previously  stated,  arch  culverts  are  more  expensive  and  more  difficult 
to  build  than  box  culverts,  but  nevertheless  they  are  frequently  used  where 
an  artistic  design  is  desirable.  The  culvert  of  5-foot  span,  illustrated  in  Fig. 
36,  is  very  similar  to  the  design  for  the  5-foot  span  shown  in  Fig.  39,  and  was 
built  in  Bureau  County,  Illinois,  by  the  Illinois  Gravel  Company  of  Princeton, 
Illinois.  It  contains  11.4  cubic  yards  of  concrete  mixed  one  part  "ATLAS" 
Portland  Cement  to  six  parts  sand  and  gravel,  using  gravel  as  the  large 
aggregate  with  coarse  sand  to  fill  the  voids.  The  cost  of  the  cement  delivered 


79 


at  the  bridge  was  $1.35  per  barrel.    Actual  cost  of  the  culvert  was  $75.00,  which 
included  long  haul  charges  for  gravel. 

Figs.  37,  38  and  39  show  designs  for  arch  culverts  of  5,  8,  and  lo-foot  clear 
spans  respectively,  suitable  for  highway  construction  where  the  soil  is  firm, 
as  compact  sand  or  hard  clay.  If  the  soil  is  soft  clay  or  loam,  the  footings 
should  be  made  wider  so  as  to  give  a  larger  bearing  area  for  the  walls  as  well 


FIG.  36.— CONCRETE  ARCH  CULVERT  IN  BUREAU  COUNTY,  ILLINOIS. 


as  for  the  arch  proper.  Of  course,  if  the  soil  is  too  soft,  box  instead  of  arch 
culverts  should  preferably  be  used,  or  else  the  bearing  power  of  the  soil 
should  be  increased  as  indicated  below  under  "Preparing  the  Bed." 

As  shown  in  Fig.  38,  each  end  wall  of  the  lo-foot  span  should  be  reinforced 
with  14  long  vertical  rods  and  with  8  short  bent  rods,  the  latter  extending 
horizontally  two  feet  into  the  arch  and  vertically  two  feet  into  the  end  walls ; 
and  in  addition  there  should  be  4  long  horizontal  rods  in  each  end  wall.  All 
rods  are  y2  inch  in  diameter.  The  5-foot  span  has  no  reinforcement  except 
5  bent  rods  to  tie  each  end  wall  to  the  arch. 

The  designs  show  a  width  of  10  feet  between  the  walls,  but  this  can  be 
increased  to  any  distance  desired. 

80 


I 

% 


ofdrch 

w/fh  earf/?  fit/ing  removed 


'E/evaf/on 

A/ofe:-  4//  rods  £  d/am 


Long/fud/na/  Sec f /on 


/9 


w/fh  earth  f/7//ng  removed. 

FIG.  37.— ARCH  CULVERT  FOR  FIVE-FOOT  SPAN. 


sj  ffewf/on 

w/fft  e&r//i  f////ng  removed 


22&O" 


/?OC/5 


/-/a/f  fnaf  ZYevafion 
.-/]// 'rods  /'° 


z 

ong/fud/nai  <Sec/ 

ion 

-i—  .-^-r  .—  — 

-  1  — 

Li  —  1 

~t 

—  1"  —  •  ~*  

1 
i 

1 

i 

^ 

\ 

T  " 
1 

1 

—  -  '—*-'  ^-^  -1 

-  HL 

1—  1- 

1-  \± 

of  /4rch  w///?  e&rfh  f/7//ng  removed 
FIG.  38.— ARCH  CULVERT  FOR  TEN-FOOT  SPAN. 

81 


ARCH  IN  BUREAU  CO.,  ILLINOIS. 


BEAM  BRIDGE,  GROTON,  MASS. 
82 


In  the  5-foot  span  there  are  4.25  cubic  yards  in  each  end  wall  and  4.73 
cubic  yards  in  the  arch  between  the  end  walls,  making  a  total  of  13.23  cubic 
yards  of  concrete  in  the  structure.  In  case  the  roadway  is  wider  than  here 
assumed,  the  total  number  of  cubic  yards  of  concrete  in  the  structure  may  be 
computed  by  adding  to  8.5  the  product  of  0.473  times  the  distance  in  feet  be- 
tween the  end  walls ;  8.5  being  the  cubic  yards  of  concrete  in  the  two  walls 
and  0.473  the  number  of  cubic  yards  of  concrete  in  one  foot  length  of  arch. 


/0/n 

y—  -ioFt 

I 

\ 

/0/n 

?L 

•i 
j 
j 
j 

K  _  _  . 

i 

H 
1 
J 
1     (^^ 

i1^ 

1 

1 

r 

¥ 

A 


/BFt 


^-Surface,    of  Flood 


Earth 


1 2.  in. 


'End  Elevation 
aFt.      All  Bods  i  in. 


//7< 


p^ 


fr   3/7-^^- 

"•py« 

•g"*     Hbngitudinal  Section 


/0/n 


14-in. 

v5/c/e  E /&  vat / on 


Plan 

FIG.  39.— ARCH  CULVERT  FOR  EIGHT-FOOT  SPAN. 


Thus,  if  the  roadway  were  16  feet  wide  instead  of  10  feet  the  total  volume 
of  concrete  in  the  culvert  is  8.5  plus  0.473  multiplied  by  16;  that  is,  8.5  plus  7.57 
or  16.07  cubic  yards. 

The  quantities  of  materials  for  arch  culverts,  5,  8  and  lo-foot  span,  are  given 
in  the  following  table. 


83 


QUANTITY  OF  MATERIAL  FOR  ARCH  CULVERTS 
Proportions:  1  Part  "ATLAS"  Portland  Cement  to  2  1-2  Parts  Sand  to  5  Parts  Gravel  or  Stone 


Materials  for  Culvert  for  10-ft.  Roadway 
(See  Figs.  37,  38  and  39) 


Extra  Material  for  Each  Additional 
Foot  Width  of  Road 


Span 

Screened 

Screened 

of 

Cement 

Sand 

Gravel 

Cement                Sand 

Gravel 

Culvert 

or  Stone 

or  Stone 

feet 

cu.  ft. 

cu.  ft. 

cu.  ft. 

cu.  ft 

5 
8 

50  bags  or  12  y>  bbls. 
80    "     "  20    "       " 

120 
190 

240 
380 

2  bags  or  %  bbl. 
3    "    "     %    " 

5 

TYz 

10 
15 

10 

115    "     "  28  y±      " 

275 

550 

4    "    "      1    " 

10 

20 

PREPARING  THE  BED. 

Culverts  should  be  built  when  the  water  is  low  in  the  brook  at  the  site  of 
the  culvert.  In  many  cases  the  water  will  cause  no  trouble  if  in  excavating 
for  the  foundation  the  earth  is  thrown  up  into  two  parallel  dams  so  that  the 
brook  can  flow  between  them,  the  foundation  for  the  culvert  being  then  laid 
outside  of  these  piles  of  earth.  Sometimes  the  stream  can  be  carried  in  a  new 
trench  around  the  side.  If  there  is  considerable  water  in  the  brook  and  it 
cannot  be  carried  around,  it  may  be  necessary  before  excavating  to  drive  a 
row  of  closely  fitting  boards  parallel  to  the  stream  in  front  of  each  of  the 
proposed  trenches  in  which  the  foundations  are  to  be  laid  and  then  bank  the 
earth  against  the  boards  to  make  two  tight  dams  between  which  the  brook 
flows  and  behind  which  the  work  may  be  carried  on.  Sometimes  the  water 
may  be  carried  in  a  box  trough  as  shown  in  Fig.  41. 

In  some  cases  a  hand  pump  may  be  needed  to  keep  down  the  water  in 
trenches.  Trenches  for  foundations  of  whatever  kind  should  in  all  cases  be 
excavated  to  a  depth  below  frost,  but  if  the  brook  is  never  dry  two  or  three 
feet  below  the  bed  of  the  stream  will  be  sufficient. 

The  preparation  of  the  bottom  of  the  trenches  to  receive  the  concrete  foot- 
ings of  the  culvert  as  a  rule  should  not  be  difficult,  for  the  concrete  can  be 
laid  directly  on  the  soil  when  it  is  hard  clay,  compact  sand  or  gravel.  If  the 
soil  is  soft  sand  or  soft  clay  or  loam  it  should  be  compacted  by  ramming,  but 
if  too  soft  to  be  rammed  the  bearing  power5  of  the  soil  can  be  increased  by 
adding  a  layer  of  clean  sand,  cinders,  or  broken  stone  before  ramming.  In 
extreme  cases,  where  the  soil  is  very  soft,  it  may  be  necessary  to  increase  the 
width  of  the  base  of  the  culvert  walls  or  to  build  these  walls  on  a  layer  of 
4-inch  planks  to  distribute  the  weight  over  a  considerable  area  of  the  soil. 

84 


Occasionally,  piles  may  be  necessary.    Where  the  soil  is  as  soft  as  here  indi- 
cated a  box  culvert  is  preferable  to  an  arch. 

Planking  should  never  be  used  under  a  foundation  unless  it  will  at  all 
times  be  covered  with  water. 


FORMS  FOR  ARCH  CULVERTS. 

The  forms  are  set  after  the  soil  has  been  prepared  to  receive  the  concrete. 
Outer  wing  wall  forms  are  generally  constructed  of  i-inch  boards  laid  hori- 
zontally and  braced  with  2  by  4-inch  or  2  by  6-inch  studs.  The  forms  on  the 
inner  side  of  the  wing  walls  are  laid  horizontally  and  cut  to  fit  approximately 
the  shape  of  the  arch.  The  outer  surface  of  the  arch  proper  needs  forms  from 
the  bottom  up  to  about  ^2  to  3^  of  the  way  to  the  top  and  should  be  made  of 
i  by  4-inch  or  i  by  6-inch  boards,  attached  at  their  ends  to  the  inside  wing 
wall  forms. 

Centering  for  circular  arch  culverts  is  shown  in  Figs.  40  and  41.  The  sills 
should  be  set  first  and  braced ;  then  the  circular  forms,  spaced  2  feet  apart  for 
i -inch  lagging,  3  to  4  feet  apart  for  2-inch  stuff,  should  be  set  upon  the  wedges 
resting  on  the  upper  sills.  The  lagging  shown  in  the  drawings,  which  should 
be  of  narrow  width  to  fit  the  circle,  is  then  fastened  to  the  circular  centers. 
The  outer  forms  must  be  braced  by  tieing  across  the  top  of  the  culvert  or  by 
using  braces  against  the  earth  on  either  side. 

In  Fig.  41  the  inside  wall  forms  have  a  3  by  4-inch  or  a  4  by  4-inch  ranger 
set  across  the  top  of  the  cleats  on  which  the  wedges  are  placed  to  support  the 
arch  forms.  The  wedges  should  separate  the  two  forms  at  least  3  inches  in 
order  to  facilitate  the  removing  of  the  arch  forms.  A  strip  of  sheet  iron  may 
be  nailed  to  the  side  forms,  as  shown,  and  lap  over  on  to  the  arch  form  to 
prevent  the  concrete  from  getting  in  between  the  forms.  After  removing  the 
arch  forms  the  side  forms  can  be  readily  removed. 

The  forms  should  be  oiled  before  placing  the  concrete. 

The  concrete  for  culverts  should  be  of  a  mushy  consistency  and  should  be 
deposited  and  lightly  tamped  in  layers  6  or  8  inches  thick.  If  possible  the 
concrete  of  the  whole  arch  and  wing  walls  should  be  deposited  at  one  time, 
but  where  the  work  is  so  large  as  to  make  it  impossible  to  do  this,  the  arch 
should  be  divided  into  circular  sections,  and  one  section  laid  at  a  time. 
Twenty-eight  days  should  be  allowed  for  the  concrete  to  set,  after  which  time 
the  wedges  are  knocked  out  and  the  centers  removed.  The  earth  filling  can 
be  placed  as  soon  as  the  connecting  is  completed. 


'Lagging  2"by3" 


FIG.  40.-  FORMS  FOR  FIVE-FOOT  CIRCULAR  ARCH. 


/?.  Lagging 


«:::\.//n  Boards 


FIG.  41.— FORMS  FOR  EIGHT-FOOT  CIRCULAR  ARCH. 
86 


CHAPTER   VI. 


BEAM  BRIDGES 

Owing  to  the  demand  for  more  permanent  bridges,  concrete  is  fast  replac- 
ing wood  and  steel  for  structures  of  all  types,  especially  for  spans  under  100 
feet.  Not  only  is  concrete  an  excellent  material  for  these  short  spans,  but! 
where  the  foundations  are  good,  concrete  arches  are  well  suited  even  for 
structures  200  feet  in  length  or  even  longer.  The  average  life  of  a  wooden 
bridge  is  only  about  9  years,  and  of  a  steel  bridge  not  over  30  to  40  years,  and 


FIG.  42.— CONCRETE  BEAM  BRIDGE. 

even  during  this  time  there  is  a  continual  outlay  for  repairs  and  painting.  A 
concrete  bridge  will  last  indefinitely  and  with  practically  no  maintenance. 

In  the  State  of  Illinois  alone  $1,888,724  was  expended  for  highway  bridges 
in  the  year  1905,  a  considerable  part  of  this  being  devoted  to  repairing  and 
replacing  wooden  or  metal  structures.  It  is  evident  that  more  attention  should 
be  given  to  the  design  and  construction  of  highway  bridges. 

In  addition  to  their  natural  permanence,  concrete  bridges  are  cheap  in  first 
cost  and  are  absolutely  proof  against  tornadoes,  high  water,  and  fire.  Further- 

87 


more,  by  employing  local  labor  the  money  spent  in  their  construction  remains 
almost  entirely  in  the  community  in  which  the  bridge  is  built,  there  is  less 
difficulty  in  securing  the  necessary  skilled  labor  during  times  when  the  build- 
ing trades  are  active  and  there  is  no  waiting  for  structural  steel  since  rods 
can  be  had  at  short  notice. 

The  greatest  care  should  be  taken  in  the  design  and  construction  of  con- 
crete bridges.  Designs  must  be  made  by  an  engineer  familiar  with  concrete 
construction  except  for  small  arched  structures  where  the  designs  given  in 
this  book  may  be  used  by  one  who  thoroughly  understands  the  use  of  concrete. 


KINDS  OF  CONCRETE  BRIDGES. 

Concrete  bridges  may  be  classified  as  flat  bridges  and  arch  bridges.  Flat 
bridges  are  those  in  which  the  pressure  from  the  bridge  acts  vertically  on  the 
supports  and  consist  either  of  straight  flat  slabs  or  of  combined  beams  and 
slabs  of  concrete  reinforced  with  steel.  Arch  bridges  are  curved  and  the 
pressures  upon  the  supports  are  not  vertical  but  inclined. 

Flat  construction  is  suitable  in  level  countries  for  short  spans,  generally 
not  exceeding  30  or  40  feet,  and  for  locations  where  the  foundation  is  soft 
material.  Arches  are  especially  economical  in  localities  where  the  roads  can 
be  built  considerably  above  the  streams  and  where  there  is  rock,  firm  sand 
or  gravel  or  other  similar  hard  soils  which  afford  good  foundations. 


TYPES  OF  FLAT  BRIDGES. 

Flat  bridges  may  be  divided  into  three  types,  slab,  combined  beam  and 
slab,  and  girder  bridges.  The  first  two  types  are  used  for  short  spans  and 
the  girder  type  is  preferably  used  for  spans  from  25  to  40  feet. 

A  slab  bridge,  Fig.  43,  consists  essentially  of  a  flat  slab  of  concrete  of 
uniform  thickness  reinforced  with  steel  and  resting  on  the  supporting  walls. 
In  some  cases,  as  shown  in  Fig.  44,  the  slab  is  supported  by  two  longitudinal 
girders.  The  macadam  roadway  is  laid  directly  on  the  slab — or  by  employing 
method  and  materials  described  in  Chapter  III  the  slab  may  form  a  concrete 
pavement. 

Combined  beam  and  slab  bridges,  Fig.  45,  consist  of  a  series  of  reinforced 
concrete  beams,  laid  parallel  to  the  roadway,  and  a  flat  slab  of  concrete  upon 
which  the  roadway  is  laid.  These  beams  rest  on,  and  are  usually  thoroughly 
united  with,  the  abutment  walls.  The  beams  and  slab  must  be  laid  at  one  time 
so  as  to  form  a  homogeneous  structure. 

88 


Girder  bridges,  Fig.  48,  are  usually  composed  of  two  large  reinforced  con- 
crete beams,  called  girders,  one  on  either  side  of  the  roadway  supporting  in- 
termediate cross  beams  which  in  turn  carry  the  slab  upon  which  the  roadway 
is  laid.  A  weight  on  the  roadway,  as  from  a  wagon  wheel  for  example,  is 
therefore  transmitted  from  the  roadway  to  the  slab,  then  to  the  beams,  then 
to  the  girders  and  finally  from  the  girders  to  the  supports. 

PROPORTIONS  FOR  CONCRETE. 

For  bridges  such  as  described  in  this  chapter,  the  concrete  should  be  mixed 
one  part  "ATLAS"  Portland  Cement,  two  parts  sand,  and  four  parts  broken 
stone  or  gravel  for  slabs,  beams,  girders,  and  other  parts  of  the  deck.  For 
abutment  walls  and  foundations  use  one  part  "ATLAS"  Portland  Cement, 
two  and  one-half  parts  sand,  and  five  parts  broken  stone  or  gravel. 

The  materials  must  be  thoroughly  mixed  and  must  not  be  separated  in 
handling. 

Care  must  be  taken  to  work  the  concrete  in  between  and  around  the  steel 
rods  without  displacing  them. 

The  forms  must  be  strong  and  under  the  bridge  they  must  be  left  in  place 
28  or  30  days  or  even  longer  in  the  fall  and  spring. 

STEEL  REINFORCEMENT. 

The  reinforcement  shown  in  the  designs  of  this  chapter  is  medium  steel, 
either  with  round  or  deformed  surfaces,  the  latter  giving  better  bond  with 
the  concrete. 

SLAB  BRIDGES. 

A  slab  bridge  similar  to  that  shown  in  Fig.  43,  representing  a  design  practi- 
cally the  same  as  the  standard  design  of  the  Pennsylvania  State  Highway 
Department,  is  of  simple  construction  and  permanent  character.  This  bridge, 
which  has  a  clear  span  of  16  feet,  consists  of  a  reinforced  slab  15  inches  thick 
connected  rigidly  to  two  abutment  walls  of  the  same  thickness.  The  side  walls 
serve  only  as  protecting  parapets.  The  principal  reinforcement  in  the  slab 
consists  of  steel  rods  %  inch  square,  spaced  5  inches  apart  on  centers,  running 
lengthwise  of  the  roadway  and  bent  at  the  abutments.  The  design  shown 
differs  from  the  standard  of  the  Pennsylvania  State  Highway  Department  in 
that  alternate  bars  are  bent  upward  at  the  junction  of  the  slab  and  abutment 
walls  so  as  to  lie  near  the  outer  surfaces  of  the  slab  and  wall.  Rods  placed  in 
these  positions  at  the  upper  corners  prevent  cracks  from  forming  in  the  con- 
crete at  the  top  of  the  slab  near  the  abutment  wall.  In  addition  %-inch  square 

89 


rods  are  used  in  the  slab,  abutments,  and  side  walls  as  shown  in  the  cut.  The 
distance  from  the  bottom  of  slab  to  top  of  upper  footing  course  is  shown  as 
6  feet,  but  this  may  be  increased  to  10  feet  if  necessary  to  give  the  proper 
waterway.  For  greater  heights  than  10  feet,  the  thickness  and  reinforcement 
of  the  walls  and  footings  should  be  increased.  The  total  length  of  each  side 
wall  also  must  be  increased  3  feet  for  every  i  foot  increase  in  the  height  over 
that  shown  in  the  cut. 


;    i 

^a 

\J 

§ 

\ 

i       5 

1 

Si 

\ 

V 

>.              \j 

C/_.  of  fibadway 

9 

669-, 

CN 

vj 

"S 

^•v. 

^ 

cl 

M 

<S 

0 

^ 

,,-'J 

1 

*^> 

^ajjsL  7^J"— *^P 

/Js 


g^fip^fp??^'1' 


/^z/"  ELEVAT/ON  \  HAtr  LOMG/TUD/NAL  SECT/ON 

FIG.  43.— SLAB  BRIDGE  WITH  SPAN  OF  16  FEET. 


The  designs  for  spans  other  than  1 6-foot,  differ  in  the  thickness  of  the 
concrete  and  in  the  amount  of  reinforcement.  Each  span  is  a  special  design 
in  itself  and  it  is  just  as  necessary  to  have  exactly  the  correct  amount  of  con- 
crete and  steel  rods  for  each  individual  design  as  it  is  to  use  the  right  size  of 
I-beams  or  trusses  in  a  steel  bridge. 


90 


The  clear  width  of  the  roadway  in  the  design  illustrated  is  20  feet,  but 
this  may  be  changed  to  suit  local  conditions,  using  for  a  1 6-foot  span  the 
same  thickness  of  slab  and  the  same  size  and  spacing  of  reinforcement. 
There  are  73  cubic  yards  of  concrete  and  4,375  pounds  of  steel  rods  in  this 
bridge.  For  every  i-foot  increase  or  decrease  in  width  of  roadway,  there  will 
be  an  increase  or  decrease  in  the  volume  of  concrete  of  1.91  cubic  yards,  and 
in  the  weight  of  steel  rods  of  125.7  pounds.  With  the  aid  of  these  figures, 
the  total  quantities  may  be  computed  for  a  bridge  having  a  roadway  whose 
width  differs  from  that  shown  in  the  drawing. 

The  accompanying  table  shows  the  proper  dimensions  and  quantities  of 
materials  for  slab  bridges  similar  to  that  illustrated  in  Fig.  43.  The  quan- 
tities of  materials  given  in  the  table  are  for  the  entire  bridge,  including  abut- 
ments, side  walls  and  slab. 

PRINCIPAL   DIMENSIONS   AND   QUANTITIES   OF   MATERIALS   FOR   SLAB   BRIDGES 

SIMILAR  TO  BRIDGE  IN  FIG.  43 


Clear 

Thick- 
ness of 

Longitudinal 
Bars 

Abutment 
Walls 

Length  of 
Side  Walls, 
Feet 

Cu.  Yds.  of 
Concrete 

Pounds  of 
Steel  Rods 

C1«K 

in  Ft. 

in 
Inches 

Size  of 
Square 

Kflrs 

Distance 
c.  to  c., 

Thick- 
ness, 

Width  of 
Footing, 

6  Ft.* 

8  Ft.* 

6  Ft.* 

8  Ft.* 

6  Ft.* 

8  Ft.* 

Inches 

Inches 

Inches 

Inches 

8 

9 

y% 

6 

8 

20 

32.0 

38.0 

43 

53 

2715 

3440 

10 

11 

% 

5 

11 

23 

34.5 

40.5 

49 

60 

3195 

3880 

12 

13 

% 

5 

13 

27 

37.0 

43.0 

57 

69 

3420 

4100 

16 

15 

Z/A 

/4 

5 

15 

45 

41.5 

47.5 

73 

87 

4375 

5035 

*Distance  in  feet  from  top  of  footing  course  to  bottom  of  slab. 


A  slightly  different  style  of  design  for  a  slab  bridge  from  that  just  de- 
scribed is  shown  in  Fig.  44,  which  represents  a  standard  design  of  the  Illinois 
State  Highway  Commission  for  a  24-foot  span  carrying  a  roadway  16  feet 
wide.  Here  the  slab  is  supported  by  the  side  girders  which  at  the  same  time 
serve  as  side  railings  or  parapets.  The  wing  walls  are  set  at  an  angle  with 
the  abutments  and  are  reinforced  with  ^-inch  rods  laid  horizontally  near 
the  front  face  and  vertically  near  the  back  face.  The  main  abutment  walls 
are  14  inches  thick  and  have  a  maximum  height  of  14  feet  4  inches  from  the 
bottom  of  the  foundation.  These  walls  as  well  as  their  foundations  are 
reinforced  with  ^-inch  bars  as  indicated  in  the  figure. 

The  floor  slab  is  u  inches  thick  and  is  reinforced  with  ^4-inch  bars,  4 
inches  apart  on  centers  running  across  the  roadway  and  bent  up  into  the  gir- 


d^S3ES5§ 


- 


FIG.  44,— SLAB  BRIDGE  WITH  SPAN  OF  24  FEET. 


ders,  also  with  %-inch  bars  spaced  12  inches  apart  on  centers  running  length- 
wise of  the  bridge.  The  reinforcement  of  the  girders  consists  of  nine  hori- 
zontal bars  imbedded  in  the  lower  part  and  several  U-shaped  bars  placed  ver- 
tically at  short  intervals  throughout  the  length  of  the  beam. 

Care  must  be  taken  to  set  the  steel  rods  in  the  places  called  for  by  the 
plans;  thus,  in  the  footings  of  the  abutment  walls  the  horizontal  rods  must 
be  near  the  bottom,  not  the  top  of  each  footing.  Rods  are  placed  in  concrete 
to  perform  certain  definite  purposes  and  too  much  care  cannot  be  taken  to 
see  that  they  are  set  right  and  that  they  do  not  get  moved  out  of  place  during 
the  progress  of  the  work. 

In  this  24-foot  span,  shown  in  Fig.  44,  there  are  82.7  cubic  yards  of  concrete 
and  7,584  pounds  of  steel. 


COMBINED   BEAM  AND   SLAB   BRIDGES. 

Combined  beam  and  slab  bridges  are  more  complicated  in  design  and  in 
construction  than  are  slab  bridges.  Inexperienced  persons  should  not  at- 
tempt the  design  of  structures  of  this  type  and  those  ignorant  of  the  use  of 
concrete  should  not  attempt  to  build  beam  and  slab  bridges. 

Combined  beam  and  slab  bridges  are  well  adapted  to  spans  of  15  to  30 
feet  where  the  width  of  roadway  is  more  than  16  or  18  feet.  Fig.  45  shows 
such  a  structure  built  of  reinforced  concrete  in  1906  by  the  Massachusetts 
Highway  Commission  and  represents  a  skew  bridge  of  28-foot  span.  The 
slab  on  which  the  macadam  roadway  is  laid  is  4  inches  in  thickness  and  is 
reinforced  with  %-incb.  square  twisted  steel  rods  spaced  8  inches  apart.  The 
slab  is  supported  by  eight  reinforced  concrete  beams  spaced  3  feet  2  inches 
apart  on  centers.  These  beams  are  28  inches  deep  under  the  slab  and  vary 
in  width  from  13  inches  on  the  bottom  to  14  inches  just  under  the  slab.  The 
reinforcement  for  each  beam  consists  of  three  longitudinal  i*4-inch  square 
twisted  rods  placed  near  the  bottom  with  ten  ^-inch  and  six  %-inch  stirrups 
placed  as  shown  in  the  longitudinal  section  of  beam. 

In  the  construction  of  concrete  beams,  such  as  that  shown  in  Fig.  45, 
running  parallel  with  the  roadway  and  resting  upon  the  abutment  cross  walls, 
the  best  design  demands  that  one  or  more  bent  bars  be  placed  in  each  end 
of  each  beam  running  vertically  into  the  wall  near  the  back  face  and  horizon- 
tally into  the  beam  near  the  top  surface  of  the  beam.  Bent  rods  of  this  kind 
tend  to  prevent  the  formation  of  cracks  in  the  upper  surface  of  the  beam  near 
the  ends.  In  the  longitudinal  beams  in  Fig.  45,  this  can  be  done  by  bending 
up  the  center  i^-inch  bar  about  3  feet  from  the  face  of  each  abutment  and 

93 


94 


continuing  this  bar  near  the  upper  horizontal  surface  of  the  beam  thence 
around  the  corner  down  into  the  abutment  walls  about  4  feet. 

The  abutments,  Fig.  45,  which  are  irregular  in  shape  on  account  of  the 
skew  on  which  the  bridge  crosses  the  stream,  are  braced  with  counterforts 
15  inches  thick  spaced  about  5  feet  apart.  Each  counterfort  has  two  ^4-inch 
tie  bars  imbedded  2^/2  inches  in  from  the  back  surface  and  bent  down  into  the 
footing  so  as  to  form  a  secure  tie.  The  footing  is  also  reinforced  with  3/g-inch 
bars  running  perpendicular  to  the  face  of  the  abutment  and  spaced  12  inches 
apart  on  centers.  The  abutment  and  wing  walls  are  15  inches  thick  and 
have  }/2-inch  horizontal  bars  spaced  from  12  to  24  inches  apart  on  centers  and 
5/g-inch  vertical  bars  6  inches  apart  on  centers. 


FIG.  46.— FORMS  FOR  SLAB  AND  BEAM  BRIDGE. 

One  hundred  and  seventy-seven  cubic  yards  of  1 12  15  "ATLAS"  Portland 
Cement  concrete  were  used  in  the  construction  of  this  bridge.  The  total  cost 
of  the  bridge  was  $2,286.50,  the  cement  costing  $2.30  at  the  nearest  railroad 
station.  The  actual  time  of  construction  was  54  days,  although  the  total  time 
elapsing  from  start  to  finish  of  the  work  was  86  days. 

In  concreting  a  combined  beam  and  slab  bridge,  the  work  must  be  con- 
tinuous so  that  the  beam  and  slab  are  placed  at  one  time,  thus  forming  a 
monolith.  This  is  a  very  important  matter  and  utmost  precautions  must  be 
taken  to  see  that  it  is  carried  out  in  the  construction  of  beam  and  slab  bridges. 

95 


FIG.  47.— FORMS  FOR  DECK  OF  COMBINED  BEAM  AND  SLAB  BRIDGE. 

96 


METHOD  OF  CONSTRUCTION  OF  COMBINED  BEAM  AND  SLAB 

BRIDGES. 

Fig.  47  shows  the  arrangement  of  forms  for  the  deck  of  a  combined  beam 
and  slab  bridge.  Generally  the  abutment  forms  are  first  set  and  the  concrete 
placed  to  the  grade  of  the  bottom  of  the  beams  in  the  deck.  The  forms  for 
the  deck  are  then  put  into  position  and  after  the  reinforcement  is  placed  the 
concrete  for  the  beams  and  slab  is  laid,  the  concrete  for  the  slab  being  placed 
immediately  after  filling  the  beam  form  below  it  and  before  the  cement  begins 
to  set.  In  some  cases  where  the  beams  underneath  the  slab  are  designed 
heavy  enough  to  act  alone  without  the  aid  of  the  slab  the  beam  reinforcement 
is  first  placed  and  the  concrete  for  the  beams  poured  into  the  forms.  Then 
the  slab  reinforcement  is  placed  in  position  and  the  concreting  of  the  slab 
started.  If,  however,  the  beams  are  designed  as  T-beams  in  the  more  usual 
and  the  cheapest  way,  it  is  absolutely  essential  that  the  beams  and  slab  be 
laid  at  the  same  operation.  The  deck  forms  should  be  thoroughly  braced 
underneath  so  that  they  will  not  deflect  as  the  concrete  is  poured. 

In  Fig.  47  the  bracing  is  only  partially  shown,  since  it  will  vary  consider- 
ably with  the  location  of  the  structure.  The  stirrups  shown  in  section  A-A 
can  best  be  held  in  place  temporarily  with  small  wooden  strips  which  are 
removed  as  soon  as  there  is  enough  concrete  in  the  beam  to  hold  the  stirrups 
in  place. 

GIRDER  BRIDGES. 

Concrete  girder  bridges  are  not  so  common  as  slab  or  combined  slab  and 
beam  bridges,  but  they  are  suitable  for  spans  longer  than  is  proper  for  the 
slab  bridges  and  for  locations  where  there  is  not  head  room  enough  to  use  an 
arch  span.  Fig.  44  is  in  one  sense  a  girder  bridge  since  it  has  two  main 
girders  which  carry  the  slab,  but  Fig.  48  gives  a  better  idea  of  this  type  of 
structure.  In  Fig.  48  the  slab  is  8  inches  in  thickness  at  the  center  and  7 
inches  at  the  girders  and  is  reinforced  with  ^4-inch  twisted  square  bars  spaced 
7  inches  apart  on  centers  running  parallel  to  the  roadway.  At  the  center  of 
each  panel,  that  is,  midway  between  the  cross  floor  beams,  these  bars  must 
be  laid  i^  inches  from  the  bottom  of  the  slab,  but  at  the  cross-beams  they 
should  be  i^  inches  from  the  top  of  the  slab,  being  bent  to  conform  to  these 
requirements.  Another  way  is  that  shown  in  Fig.  48,  where  the  rods  in  the 
bottom  of  the  slab  are  run  through  straight  over  the  floor  beams  and  another 
set  of  3^-inch  bars  4  feet  long  spaced  7  inches  apart  on  centers  is  laid  parallel 
with  the  length  of  the  roadway  and  imbedded  in  the  top  of  the  slab  over  the 
floor  beam.  At  the  end  of  the  bridge  where  the  slab  connects  with  the  end 

97 


R 


floor  beam,  the  rods  in  the  top  of  the  slabs  should  be  bent  to  extend  downward 
into  the  floor  beam. 

The  floor  beams,  which  are  the  cross-beams  running  from  girder  to  girder, 
are  spaced  10  feet  apart  on  centers  and  are  reinforced  with  five  ^4-inch  longi- 
tudinal bars  and  with  3/8-inch  stirrups.  These  longitudinal  rods  must  be  bent 
up  at  each  of  the  floor  beams  as  shown  and  must  extend  into  the  girder. 

The  main  girders  have  a  clear  span  of  37  feet  and  a  depth  of  5  feet.  They 
are  reinforced  with  eight  i^-inch  square  bars  in  the  bottom  and  three  i*4- 
inch  square  bars  in  the  top  and  are  provided  with  vertical  stirrups.  The  stir- 
rups are  %-inch  bars  bent  U-shaped  and  placed  close  together  near  the  ends 
of  the  girder  and  further  apart  near  the  center. 

The  surface  of  the  roadway  must  be  drained  and  this  can  best  be  done  by 
making  a  slab  with  a  curved  upper  surface  so  that  the  water  may  run  to  the 
gutters  and  thence  through  the  drain  pipes  placed  in  the  slab. 


FIG.  49.— REINFORCED  CONCRETE  ROADWAY  FOR  STEEL  SPANS. 

CONCRETE  FLOORS  FOR  STEEL  BRIDGES. 

On  long  span  highway  bridges  where  steel  trusses  are  necessary,  plank 
flooring  has  until  recently  been  used,  but  as  this  planking  only  lasts  from  one 
to  five  years  there  is  a  demand  for  something  more  durable  than  wood  and 
reinforced  concrete  slabs  on  steel  beams  are  being  used. 

Fig.  49  shows  a  typical  cross  section  of  a  concrete  slab  construction  carried 
on  steel  I-beam  stringers  which  in  turn  are  supported  by  the  steel  floor  beams 
running  from  truss  to  truss.  A  so-foot  roadway  without  sidewalks  is  here 
provided  for,  but  where  sidewalks  are  necessary  the  construction  may  be  easily 
modified  to  suit.  The  wearing  surface  of  the  roadway  is  shown  as  asphalt, 
which  usually  is  laid  2  inches  thick  on  a  binder  of  small  thickness.  In  some 
cases  the  binder  has  been  omitted  and  the  upper  surface  of  the  concrete  left 

99 


very  rough  to  give  a  good  union  between  asphalt  and  concrete.  Proper  crown 
must  be  given  the  roadway  to  take  care  of  the  drainage ;  this  being  easily  done 
by  setting  the  I-beam  stringers  on  high  levels  towards  the  center  of  the  road- 
way or  else  by  making  the  concrete  slab  level  and  using  a  greater  thickness  of 
wearing  surface  at  the  center  than  at  the  gutters. 

The  I-beam  stringers  should  be  encased  in  concrete  as  shown,  for  by  so 
doing  a  stronger  floor  is  obtained  and  the  steel  beams  are  protected  against 
rust.  Railing  posts  made  of  two  steel  angles  and  connected  to  the  outside  I- 
beam  by  a  plate  and  small  angles,  give  the  necessary  support  to  the  railings. 

COST  OF  BEAM  AND  SLAB  BRIDGES. 

There  is  considerable  variation  in  the  cost  of  concrete  bridges  and  any  data 
given  regarding  the  cost  is  at  the  best  only  approximate.  The  cost  of  a  bridge 
is  affected  by  the  span,  width,  height,  character  and  depth  of  foundations,  the 
type  of  structure,  the  magnitude  of  the  loads  to  be  carried,  the  style  of  finish, 
and  by  several  other  elements  of  a  similar  nature. 

The  cost  of  several  reinforced  concrete  bridges  recently  built  and  similar  to 
those  shown  in  this  chapter,  was  $9.00  per  cubic  yard  for  the  reinforced  con- 
crete where  the  expense  of  hauling  was  considerable,  and  $6.75  per  cubic  yard 
for  abutments  without  reinforcement.  The  abutment  foundations  extended 
about  3  feet  into  the  ground. 

For  reinforced  concrete  bridge  work  similar  to  that  shown  in  Fig.  43,  the 
contract  price  frequently  paid  by  the  Pennsylvania  State  Highway  Commis- 
sion is  $10.00  per  cubic  yard. 

A  bridge  of  30  feet  span  similar  to  the  one  shown  in  Fig.  44  and  designed 
by  the  Illinois  Highway  Commission  cost  $995  not  including  the  crushed  stone 
which  was  furnished  free.  The  price  of  the  bridge  would  have  been  $1,125  had 
the  contractor  furnished  everything.  There  were  90  cubic  yards  of  concrete 
and  8,600  Ibs.  of  steel  in  the  structure.* 


^Illinois  Highway  Commission  Report,  1906,  p.  59. 

100 


CHAPTER  VII. 

ARCH  BRIDGES. 

Arches  include  that  class  of  curved  bridges  varying  from  simple  culverts  of 
5  or  lo-foot  spans  to  the  wonderful  structures  like  the  Walnut  Lane  Bridge  in 
Philadelphia  which  has  an  arch  of  232  feet,  clear  span.  The  advantage  of 
using  concrete  in  bridges  was  clearly  set  forth  in  Chapter  VI.  and  therefore  it 
is  needless  to  further  emphasize  in  this  chapter  on  arch  bridges,  its  value 


AUBURN  ST.  BRIDGE,  MEDFORD,  MASS. 

wherever  ultimate  economy,  beauty  and  durability  are  of  importance.  Suffice 
it  to  say  that  in  many  locations  a  good  concrete  arch  bridge  can  be  built 
cheaper  than  a  good  steel  bridge,  and  when  the  durability  of  the  concrete  and 
the  enormous  cost  of  maintaining  the  steel  bridge  are  considered  there  is  no 
question  as  to  which  is  the  better  investment  for  a  town  or  county  to  make. 
The  concrete  structure  is  more  durable,  more  beautiful,  and  in  every  way  supe- 
rior to  steel  construction  for  spans  of  ordinary  length.  Where  the  foundations 
are  good,  a  series  of  arches  may  be  used  in  place  of  a  steel  bridge  with  long 
spans,  and  the  advantages  already  enumerated  for  short  spans  apply  equally 
well  in  this  case.  The  pressures  which  the  arch  exerts  on  its  foundations  are 


101 


inclined  and  this  pressure  or  outward  thrust  must  be  provided  for  in  the  design 
and  construction  of  the  bridge. 

PLAIN  AND  REINFORCED  CONCRETE  ARCHES. 

Arches  may  be  built  either  with  or  without  steel  reinforcing  bars;  where 
there  is  no  steel  the  arch  is  of  plain  concrete,  and  if  steel  rods  or  steel  in  other 
forms  are  used  to  reinforce  the  concrete  the  structure  is  then  called  a  reinforced 
concrete  arch  bridge. 

Steel  reinforcements  should  always  be  used  in  arches,  for  while  it  adds  very 


BRIDGE  IN  DELLWOOD  PARK,  JOLIET,  ILL. 

little  to  the  cost,  it  increases  the  strength  considerably.  In  the  last  few  years 
there  has  been  a  remarkable  increase  in  the  number  of  reinforced  concrete  arch 
bridges,  and  they  are  giving  perfect  satisfaction.  In  most  cases  the  quantity  of 
steel  used  is  really  very  small  in  proportion  to  the  quantity  of  concrete,  and  as 
this  steel  is  entirely  imbedded  in  the  concrete  it  cannot  rust  and  therefore  is  not 
open  to  the  same  objections  that  are  raised  against  steel  where  it  is  exposed  to 
the  action  of  the  elements.  In  many  arches  the  cross-sectional  area  of  the  steel 
used  is  only  about  i/ioo  of  the  area  of  the  concrete  as  measured  at  the  crown 
of  the  arch,  which  is  the  highest  part  of  the  span.  This  means  that  for  every 
100  square  inches  of  concrete  there  is  only  i  square  inch  of  steel  at  that 
section. 

102 


Under  ordinary  conditions  bridges  of  spans  from  20  or  30  feet  to  100  feet 
can  be  readily  constructed  of  reinforced  concrete,  while  for  even  greater  spans 
where  the  foundations  are  good,  the  proper  combination  of  steel  and  concrete 
makes  a  strong,  graceful  and  economical  bridge,  a  type  which  is  being  widely 
adopted  in  country  districts  as  well  as  in  the  larger  towns. 

HISTORY  OF  CONCRETE  ARCHES. 

The  first  plain  concrete  arch  built  was  the  n  6-foot  span  at  Fontainebleu 
Forest  in  France,  which  was  finished  in  1869,  and  is  known  as  the  Grand  Maitre 
bridge.  In  the  United  States  the  first  plain  concrete  arch  of  which  there  is  any 
record  was  one  of  31 -foot  span  built  in  1871  in  Prospect  Park,  Brooklyn.  The 
earliest  reinforced  concrete  arch  in  the  United  States  was  constructed  in 
Golden  Gate  Park  in  San  Francisco  in  1889,  and  several  years  even  before  this 
date  concrete  bridges  reinforced  with  iron  had  been  built  in  Europe.  This 
type  of  construction  is  not  an  experiment.  It  represents  the  highest  art  of 
modern  bridge  construction.  As  a  material  for  highway  bridges  of  spans  from 
about  30  feet  to  100  feet  reinforced  concrete  has  no  equal. 

As  has  already  been  stated,  a  span  of  232  feet  has  been  completed  in  Phila- 
delphia. The  new  Rocky  River  Bridge  in  Cleveland,  Ohio,  is  being  con- 
structed with  a  span  of  280  feet  and  a  proposed  bridge  in  New  York  City  has  a 
span  of  over  700  feet.  These  large  spans  show  the  rapid  development  in  the 
art  of  building  bridges  with  concrete. 

TYPES  OF  CONCRETE  ARCHES. 

Arches  are  classified  in  various  ways,  but  the  most  simple  classification  is 
that  which  deals  with  the  method  of  the  construction  of  the  spandrels  which 
are  the  spaces  above  the  upper  surface  of  the  arch  ring  and  below  the  roadway 
level.  These  spaces  may  be  either  filled  in  solid  with  earth  filling  or  they  may 
be  left  open  by  supporting  the  roadway  above  on  slabs  and  beams,  which  in 
turn  are  supported  on  columns  or  cross-walls  resting  on  the  arch  ring. 

Where  the  spandrel  spaces  are  filled  in  solid  with  earth,  this  earth  is  pre- 
vented from  flowing  out  sidewise  by  side  walls,  also  called  spandrell  walls, 
which  run  lengthwise  of  the  bridge,  one  on  either  side  of  the  roadway.  The 
earth  rests  directly  on  the  outer  surface  of  the  arch  ring  and  the  road  or  street 
pavement  is  laid  directly  on  this  earth  filling.  These  bridges  are  said  to  have 
solid  spandrels. 

In  the  second  type,  where  the  spandrels  are  left  more  or  less  open,  the  road- 
way is  usually  laid  on  a  slab  of  reinforced  concrete  having  a  thickness  of  from 
4  to  8  inches  which  rests  upon  a  series  of  reinforced  beams  supported  on  col- 

103 


umns,  or  upon  transverse  concrete  walls  which,  being  spaced  at  distances  of 
from  10  to  20  feet  lengthwise  of  the  bridge,  give  the  appearance  of  open  span- 
drels. These  columns  or  walls  rest  on  top  of  the  arch  ring. 

For  small  arches  the  solid  spandrel  type  is  the  most  common,  while  for  the 
large  bridges  with  spans  over  100  feet  the  open  spandrels  are  better,  because 
they  lessen  the  weight  to  be  carried. 

Arches  are  often  also  classified  as  to  the  style  of  reinforcement  or  as  to 
whether  there  are  any  hinges  used  in  the  arch  ring.  A  hinge  is  made  by  insert- 
ing a  joint  in  the  concrete  arch  ring,  and  usually,  when  they  are  used,  one  is 


FIG.  50.— ARCH  BRIDGE,   DELLWOOD  PARK,  JOLIET,  ILLINOIS. 

placed  at  the  crown  of  the  arch  and  also  one  at  each  end  where  the  arch  ring 
rests  upon  the  abutment  or  support.  These  hinges  are  made  of  steel  and  act 
very  much  in  principle  like  the  hinges  on  an  open  door,  that  is,  the  concrete 
arch  ring  can  move  a  little  by  turning  around  the  steel  hinges.  This  movement 
is  of  course  very  small.  Hinges  are  used  with  an  idea  of  simplifying  the 
design  of  the  arch,  but  they  have  been  employed  in  only  a  few  cases  in  the 
United  States. 


PREPARATION  OF  PLANS. 

An  arch  bridge  is  too  important  a  structure  to  be  placed  in  charge  of  an 
inexperienced  man.  The  only  safe  way  is  to  employ  a  competent  engineer  to 
prepare  plans  and  specifications  and  to  superintend  the  construction.  Before 

104 


the  contract  for  the  bridge  is  let,  the  plans  should  be  complete  and  should  show 
not  only  the  principal  dimensions  of  the  structure,  but  they  should  also  show 
all  important  details  which  may  in  any  way  affect  the  strength  or  the  cost. 
Unless  the  plans  and  specifications  are  complete  and  accurate,  unnecessary 
delays  in  construction  and  extra  charges  for  changes  and  additions  will  inev- 
itably occur.  If  the  engineer  is  not  to  be  on  the  ground  continually  during  the 
construction,  he  should  be  allowed  a  competent  assistant  or  inspector  whose 
duty  it  should  be  to  see  that  the  plans  and  specifications  are  followed  and  that 
the  work  is  carried  on  in  a  proper  manner. 

DESIGN  FOR  A  4o-FOOT  SPAN. 

Fig.  51  shows  a  design  for  a  reinforced  concrete  highway  arch  for  a  4O-foot 
span  with  a  rise  of  8  feet.  The  principal  parts  are  the  arch  ring,  the  spandrel 
or  side  walls,  the  abutments,  the  wing  walls,  the  parapets  and  the  earth  filling. 
The  cross  section  at  crown  shows  a  2o-foot  roadway  with  a  6-foot  sidewalk  on 
either  side.  At  the  crown  of  the  arch  the  earth  filling  has  a  thickness  of  18 
inches  at  the  center  of  the  roadway. 

The  arch  ring  is  12  inches  thick  at  the  crown  and  2  feet  6  inches  thick  at  the 
abutments,  the  latter  being  the  radial  not  the  vertical  thickness.  The  dimen- 
sions of  the  abutments  are  shown  in  the  drawing  and  have  been  determined  on 
the  assumption  that  the  soil  under  the  foundations  is  good  compact  sand  and 
gravel  or  other  similar  materials  capable  of  safely  sustaining  4000  to  6000  Ibs. 
per  square  foot. 

The  arch  ring  is  reinforced  with  round  medium  steel  rods  ^4  mcn  in  dia  Di- 
eter running  lengthwise  of  the  span,  arranged  in  two  layers,  one  layer  2  inches 
in  from  the  outer  curved  surface  of  the  concrete  ring  and  the  other  2  inches 
from  the  inner  curved  surface.  These  layers,  therefore,  are  8  inches  apart  at 
the  crown  and  2  feet  2  inches  apart  at  the  abutments.  The  rods  in  each  layer 
are  8  inches  apart  on  centers  as  shown  in  the  cross  section. 

In  addition  to  the  %-inch  rods  there  are  two  sets  of  %-inch  diameter  rods 
running  at  right  angles  to  the  length  of  the  roadway  as  shown  in  the  one-half 
longitudinal  section.  In  each  layer  the  ^4-inch  rods  are  15  inches  apart  on 
centers.  Stirrups  made  of  %-inch  diameter  round  rods  are  frequently  used  in 
bridges  of  this  type  to  connect  the  outer  layer  with  the  inner.  They  should  be 
hooked  at  the  outer  and  inner  ends  to  pass  around  the  transverse  and  longi- 
tudinal rods  at  their  intersections.  In  the  bridge  shown,  this  arrangement 
would  space  them  15  inches  apart.  Where  no  stirrups  are  used,  the  transverse 
and  longitudinal  rods  should  be  connected  by  wires  at  their  intersections. 

Where  the  design  calls  for  rods  longer  than  can  be  obtained  in  one  length, 
splices  must  be  used  and  this  can  be  done  by  simply  lapping  the  two  bars  to 

105 


io6 


be  spliced  a  distance  equal  to  20  diameters  of  the  rod  if  it  has  deformed  sur- 
faces or  30  diameters  if  it  has  smooth  surfaces.  Sometimes  the  rods  are  lapped 
and  then  wound  with  heavy  wire.  Some  designers  thread  the  rods  and  splice 
them  by  means  of  sleeve  nuts,  but  usually  it  is  sufficient  to  lap  the  rods  as 
indicated. 

As  shown  in  the  cross  section  at  the  crown,  Fig.  51,  six  ^-inch  diameter 
rods  should  be  placed  in  the  parapet  wall  between  the  expansion  joints. 

The  design  shown  is  suitable  for  ordinary  highway  traffic. 

EXPANSION  JOINTS. 

Each  spandrel  wall  and  parapet  is  provided  with  an  expansion  joint  at  the 
abutments.  This  is  to  allow  for  the  change  in  length  of  these  parts  due  to 
changes  in  temperature.  Concrete  changes  its  length  about  %-inch  for  every 
100  feet  of  length  due  to  the  change  in  temperature  from  a  mean  temperature 
to  extreme  heat  or  to  extreme  cold  in  a  climate  such  as  that  of  New  England, 
Michigan  or  similar  sections.  Unless  the  wall  is  properly  reinforced,  expansion 
joints  should  be  left  at  distances  apart  not  much  over  40  feet  or  even  less  to 
prevent  cracking  due  to  these  changes  in  temperature.  These  joints  should  be 
made  from  the  upper  surface  of  the  arch  ring  to  the  top  of  the  parapet  and 
should  be  made  wedge-shaped  or  dove-tailed  so  that  one  part  fits  into  the  other. 

REINFORCED  CONCRETE  ARCH,  ELM  STREET,  CONCORD,  MASS 

Figs.  52  and  53  show  a  highway  bridge  of  75  feet  clear  span  built  of 
"ATLAS  "Portland  Cement  in  Concord,  Massachusetts,  by  the  Massachusetts 
Highway  Commission.  The  rise  of  the  arch  is  12  feet  or  about  1/6  of  the  span 
length.  At  the  crown  the  arch  ring  is  16  inches  in  thickness  and  increases 
towards  the  abutments  as  shown. 

The  reinforcement  in  the  arch  ring  consists  of  i-inch  longitudinal  twisted 
steel  bars  spaced  17  inches  apart  on  centers  and  %-inch  transverse  twisted 
steel  bars  spaced  24  inches  apart  on  centers.  The  centers  of  the  i-inch  rods 
are  2^4  inches  from  the  face  of  the  concrete  and  these  rods  are  in  lengths  of 
about  1 6  feet  lapped  40  inches  at  each  splice  as  shown  in  Fig.  55.  Reinforced 
side  walls  braced  with  counterforts  shown  in  Fig.  53  serve  to  retain  the  earth 
filling.  Although  there  is  a  comparatively  small  amount  of  concrete  used  in 
the  construction  of  this  type  of  wall,  the  saving  due  to  this  is  probably  more 
than  offset  by  the  increase  in  cost  due  to  the  expensive  forms  necessary  for 
the  counterforts.  Several  sections  of  these  side  walls  are  shown  in  the  upper 
right  hand  corner  of  the  drawing  over  the  half  section  of  the  arch,  and  the 
locations  of  these  sections  are  indicated  by  distances  on  the  half  section  and 

107 


by  letters  upon  the  plan  of  the  arch.  The  steel  in  the  side  walls  consists  of 
s/s-inch  horizontal  rods  spaced  12  inches  apart  on  centers  near  the  bottom  and 
^/2-inch  rods  spaced  24  inches  apart  on  centers  near  the  top  of  the  wall.  In  the 
coping  there  are  also  two  %-inch  longitudinal  rods.  The  counterforts  are  pro- 
vided with  tie  rods  as  indicated. 

As  shown  in  Fig.  53,  the  coping  overhangs  the  face  of  the  arch  ring  and  the 
face  of  the  wing  walls  by  1^2  inches,  the  faces  just  mentioned  being  in  the 
same  vertical  plane ;  the  spandrel  walls  are  set  back  i  ^2  inches  from  the  face  of 
the  arch  ring,  hence  3  inches  back  from  the  surface  of  the  coping.  This  gives 
a  neat  design  and  one  which  is  easily  carried  out. 

Four  hundred  and  fifty-eight  cubic  yards  of  concrete  were  used  in  this 
structure. 


FIG.  52.— ARCH  BRIDGE  WITH  SPAN  OF  75  FEET,  ELM  STREET,  CONCORD,  MASS. 

Fig.  54  on  page  no  is  a  view  taken  just  after  the  falsework  and  centering 
were  in  place  and  before  the  lagging  was  placed  on  the  centering.  The  pho- 
tograph on  page  no  shows  the  arch  ring  under  construction  with  the  longitudi- 
nal rods  partially  imbedded  in  concrete.  One  of  the  small  transverse  rods  may 
be  seen  just  beyond  the  top  of  the  transverse  stop  boards.  These  stop  boards 
serve  as  temporary  forms  for  the  concrete  and  also  as  spacers  for  the  longi- 
tudinal rods.  After  these  boards  are  removed  the  next  section  of  the  concrete 

108 


FIG.  54.— CENTERING  OF  ARCH  BRIDGE,  ELM  STREET,  CONCORD,  MASS. 


FIG.  55.— CONSTRUCTION  OF  ARCH  BRIDGE,  ELM  STREET,  CONCORD,  MASS. 

no 


for  the  arch  ring  is  deposited  against  the  finished  section.  The  form  of  arch 
here  shown  is  suitable  for  locations  where  the  foundation  is  of  the  hardest 
material,  like  hard  pan  or  rock. 

FALSEWORK  AND  CENTERING. 

The  falsework  and  centering,  Fig.  56,  constitute  that  part  of  the  temporary 
wood  work  which  supports  the  concrete  while  it  is  being  laid  and  until  it  has 
hardened.  The  falsework  consists  of  vertical  timbers  braced  transversely  and 
longitudinally  upon  which  rest  the  centering  or  curved  platform  forming  the 
support  for  the  concrete  arch  ring.  The  vertical  supports  may  be  either  piles 
driven  into  the  ground  or  river  bottom  underneath  if  the  bottom  is  soft,  or 
framed  trestle  bents  resting  on  horizontal  timbers  if  the  bottom  is  hard.  The 
piles  must  be  placed  close  enough  to  carry  the  weight  above  with  practically 
no  settlement  and  must  be  braced  with  2  by  8-inch  or  2  by  lo-inch  diagonal 
timbers  spiked  or  bolted  to  the  piles. 

Transversely  to  the  length  of  the  bridge  and  spiked  or  bolted  to  the  tops  of 
the  piles,  a  cap  must  be  set  and  upon  these  caps  rest  wooden  wedges  support- 
ing the  weight  of  the  centering  above. 

The  centering  consists  usually  of  a  set  of  caps  or  cross  timbers  resting  on 
the  wedges  above  the  pile  caps,  some  longitudinal  stringers  notched  on  and 
supported  by  the  upper  caps  and  finally  of  a  closely  laid  flooring  or  lagging  rest- 
ing on  the  stringers.  The  caps  for  the  centers  are  usually  10  by  10  inch  or  12 
by  12  inch  timbers.  The  stringers  are  of  varying  size,  depending  on  the  dis- 
tance between  piles  and  the  weight  to  be  carried.  For  arches  having  spans  up 
to  100  feet,  these  stringers  are  from  2  to  4  inches  wide  and  from  12  to  14  inches 
deep,  spaced  from  i^  to  3  feet  apart  on  centers.  The  upper  surface  of  the 
stringers  must  be  curved  to  fit  the  curvature  of  the  under  surface  of  the  arch ; 
this  is  frequently  done  by  nailing  a  curved  piece  to  the  top  of  the  stringers  as 
in  the  centering  of  the  Concord  Arch  in  Fig.  54  and  also  in  Fig.  56.  The 
stringers  must  be  braced  to  one  another  by  i  by  6-inch  bridging  as  is  common 
in  ordinary  house  floors. 

Lagging,  consisting  of  ^4-inch  tongued  and  grooved  pine  or  2-inch  spruce 
with  beveled  edges,  must  be  nailed  to  the  stringers  and  must  be  planed  on  the 
top  side  to  give  a  smooth  finish  to  the  under  surface  of  the  arch  ring.  Some- 
times where  the  stringers  are  quite  far  apart  4-inch  lagging  is  used. 

PLACING  CONCRETE. 

Before  concreting  is  begun,  the  forms  for  the  foundations  and  wing  walls 
should  be  in  place  and  thoroughly  braced  and  the  steel  reinforcement  set  and 
wired  in  place.  The  forms  and  steel  for  the  spandrel  walls  and  the  arch  ring 

in 


FIG.  56.— FALSEWORK  AND  CENTERING  FOR  ARCH  WITH  SPAN  OF  40  FEET. 

ZI2 


may  be  placed  while  the  concrete  is  being  deposited  for  the  foundations.  As 
soon  as  the  concrete  in  the  foundations  is  up  to  the  arch,  the  arch  may  be 
begun  and  laid  in  one  or  two  days. 

First,  the  arch  ring  may  be  divided  longitudinally  into  parallel  rings  or  sec- 
tions having  a  width  of  from  3  to  5  feet,  or  even  more  if  the  span  is  not  too 
large,  and  one  of  these  sections  laid  at  a  time.  This  is  generally  the  best  plan 
to  follow. 

Or,  secondly,  the  arch  ring  is  divided  into  sections  as  shown  in  Fig.  55, 
which  shows  the  Concord  Arch  being  laid  in  large,  separate  blocks  across  the 


FIG.  57.— CENTERING  FOR  ARCHfcIN  PLACE. 

bridge,  having  a  width  equal  to  that  of  the  arch  ring  and  a  length  equal  to  a 
fraction  of  the  span  length. 

Whichever  of  these  methods  is  used,  care  must  be  taken  to  avoid  undue  set- 
tlement or  distortion  of  the  centers  as  the  concreting  progresses.  If  the  second 
method  of  laying  concrete  is  used,  that  is,  in  large  transverse  blocks,  the  work 
is  usually  begun  at  each  abutment  at  the  same  time,  and  if  the  centering  is  not 
well  supported  underneath  it  will  rise  at  the  crown,  due  to  the  weight  at  the 
two  ends.  To  avoid  this  the  best  way  is  to  begin  concreting  at  the  two  abut- 
ments and  as  this  work  progresses  load  the  centering  at  the  crown  temporarily, 
adjusting  this  load  if  needs  be  to  keep  the  centers  in  proper  position.  The 
loading  at  the  crown  is  frequently  done  by  laying  a  part  of  the  arch  ring  there 

113 


after  a  part  is  laid  at  each  abutment.     Then  the  spaces  between  these  blocks 
are  filled  in. 

For  small  arches  the  entire  ring  can  be  laid  in  one  day's  work,  and  of  course 
this  should  be  done  whenever  possible. 

EARTH  FILLING. 

After  the  concrete  is  placed  in  position  and  thoroughly  hardened  and  before 
the  centers  are  removed,  the  earth  filling  should  be  added.  As  the  earth  is 
placed,  it  should  be  compacted  by  ramming  or  rolling,  and  even  if  the  centers 
are  still  in  place  it  is  better  to  deposit  the  earth  in  layers  over  the  whole  length 
of  the  span  so  that  the  arch  is  loaded  nearly  uniformly  till  the  entire  filling  is 
in  place. 

If  the  filling  is  placed  after  the  centers  are  removed,  it  is  absolutely  neces- 
sary to  place  the  earth  uniformily  over  the  span  length  and  not  pile  a  large 
weight  on  one  side  leaving  the  other  side  unloaded. 

In  case  the  finished  roadway  is  to  have  a  surface  such  as  macadam  or  con- 
crete, great  care  should  be  taken  in  compacting  the  earth  filling,  for  otherwise 
settlement  will  take  place  in  the  filling  and  the  roadway  surface  will  also  settle. 

STRIKING  CENTERS. 

By  striking  centers  is  meant  the  lowering  of  the  centers  so  that  the  arch 
becomes  self  supporting.  The  centers  are  usually  lowered  by  removing  the 
wooden  wedges  already  mentioned  under  the  head  of  Falsework  and  Center- 
ing. These  wedges,  Fig.  56,  placed  between  the  caps  of  the  falsework  and 
those  of  the  centers,  can  be  removed  by  a  sledge  hammer,  thus  lowering  the 
centers.  Care  must  be  taken  to  lower  the  centers  gradually  and  without 
jarring  the  structure  by  allowing  a  part  to  get  its  load  suddenly. 

SURFACE  FINISHING. 

In  many  structures  the  appearance  of  the  surface  of  the  finished  concrete  is 
of  no  importance,  but  most  structures,  such  as  bridges,  which  are  constantly 
exposed  to  view,  need  some  treatment  to  render  the  outer  surfaces  neat  in 
appearance.  Oftentimes  the  structure  is  such  that  proper  selection  of  good 
tongued  and  grooved  planking  smoothly  laid,  together  with  care  in  placing 
the  concrete  against  the  forms  is  all  that  is  required  to  give  a  fairly  presentable 
surface.  This  surface  is  obtained  by  simply  forcing  a  spade  down  the  side  of 
the  forms  and  pushing  back  the  stones  so  that  the  mortar  will  flow  against 
the  face  of  the  forms  and  fill  all  stone  pockets  or  voids. 

If  a  better  finish  is  desired,  good  results  can  be  obtained  by  removing  the 

114 


forms  before  the  concrete  has  set  very  hard,  generally  from  12  to  48  hours, 
depending  upon  the  cement,  weather  and  amount  of  water  used  in  mixing,  and 
after  floating  the  green  concrete  with  water  by  rubbing  the  surface  with  a  cir- 
cular motion  with  carborundum  bricks  or  with  bricks  composed  of  i  part 
"ATLAS"  Portland  Cement  to  2  parts  sand.  If  the  concrete  can  be  worked 
when  quite  green,  a  very  satisfactory  finish  can  be  obtained  by  rubbing  the 
surface  with  stiff  wire  brushes. 

When  the  surface  of  the  concrete  has  set  so  hard  as  to  prevent  its  being 
treated  by  rubbing  with  a  brush,  it  still  may  be  surfaced  with  a  carborundum 
block,  or  an  excellent  finish  may  be  gained  by  picking  the  concrete  surface 
with  a  hand  or  pneumatic  tool  after  the  forms  are  removed.  If  further  treat- 
ment is  deemed  necessary  the  tooled  surface  may  be  washed  with  a  weak  solu- 
tion of  acid  and  then  with  an  alkali  solution  to  neutralize  the  effect  of  the  acid. 

If  a  very  smooth  surface  is  desired,  a  veneer  of  mortar  is  sometimes  placed 
between  the  main  body  of  the  concrete  and  the  forms.  This  mortar  facing  is 
usually  composed  of  i  part  "ATLAS"  Portland  Cement  to  2  or  3  parts  sand 
and  may  be  applied  in  several  ways.  Perhaps  the  cheapest  and  easiest  method 
is  to  trowel  a  layer  of  mortar  an  inch  in  thickness  against  the  face  of  the  forms 
and  immediately  deposit  the  concrete  against  it,  thus  causing  the  two  parts  to 
become  thoroughly  united.  Another  method  is  to  hold  the  concrete  away  from 
the  forms  about  i  inch  by  means  of  sheet  iron  plates  while  the  mortar  is  being 
placed  between  the  plates  and  the  forms. 

A  granolithic  finish  is  given  the  exposed  surfaces  of  bridges  in  Philadelphia 
by  applying  a  i-inch  layer  composed  of  i  part  cement  to  2  parts  sand  to  3  parts 
broken  stone  to  the  inner  surface  of  the  forms  slightly  in  advance  of  the  con- 
crete body.  After  24  or  48  hours  the  forms  on  the  faces  of  the  bridge  are 
removed  and  the  concrete  surface  is  immediately  rubbed,  using  a  wood  block 
with  sand  and  water  and  then  washing  with  clean  water. 

Plastering  on  concrete  surfaces  exposed  to  the  weather  should  be  avoided 
as  the  plaster  is  sure  to  peel  off  and  leave  the  surface  in  an  unsightly  condition 
unless  extraordinary  precautions  are  taken.  If  plastering  is  unavoidable  the 
forms  must  be  wet  instead  of  greased.  The  surface  of  the  concrete  should  be 
picked  or  bush  hammered  to  make  it  rough,  thoroughly  wet  and  then  covered 
with  a  thin  coat  of  neat  cement  paste  upon  which  the  plaster  must  be  applied 
in  as  thin  a  layer  as  possible  and  before  the  neat  cement  paste  has  set. 


COST. 

There  are  so  many  variable  items  in  bridge  building  that  to  give  accurate 
figures  regarding  costs  is  practically  impossible.  Frequently  the  cost  is  given 
for  a  bridge  based  on  a  cubic  yard  of  concrete  as  a  unit,  while  in  other  cases 

"5 


the  cost  per  horizontal  square  foot  of  roadway  surface  is  taken  as  a  unit.  In  a 
paper  read  by  Mr.  Henry  H.  Quimby  before  the  National  Association  of 
Cement  Users  in  Cleveland,  Jan.  11-16,  1909,  he  states  that  the  average  cost 
per  cubic  yard  of  18  concrete  bridges  recently  built  in  Philadelphia  was  $9.75, 
with  a  minimum  of  $6.50  and  a  maximum  of  $11.25  Per  cubic  yard.  Basing 
the  cost  on  a  horizontal  area  equal  to  the  clear  span  times  the  width,  he  gives 
as  an  average  cost  for  these  bridges  $6.50  per  square  foot,  with  a  range  of  from 
$3.11  to  $9.74  per  square  foot.  These  figures  include  all  the  concrete  in  the 
arches  and  abutments. 

The  cost  of  the  O'Connor  Street  reinforced  concrete  skew  arch  bridge  in 
Ottawa*,  Canada,  was  $8.02  per  cubic  yard  as  an  average  cost  for  the  total  of 
620  cubic  yards  including  some  plain  and  some  reinforced  concrete.  The  cost 
of  the  reinforced  concrete  was  $9.80  per  cubic  yard.  This  bridge  has  a  span 
of  20  feet;  a  length  of  46  feet;  thickness  at  crown  18  inches;  a  rise  of  4  feet  10 
inches. 

The  cost  of  two  concrete  arches,  one  of  so-foot  and  the  other  of  44-foot 
span,  built  by  the  Pennsylvania  State  Highway  Department  in  1907  is  given 
by  Mr.  G.  A.  Flinkt  as  $7.50  per  cubic  yard  for  the  44-foot  span  which  contains 
243  cubic  yards  of  concrete,  and  $9.50  per  cubic  yard  for  the  so-foot  span  con- 
taining 268  cubic  yards.  The  so-foot  span  has  a  rise  of  6  feet  9  inches,  which 
is  quite  small  for  a  bridge  of  this  length. 


*The  Concrete  Review,  Vol.  3,  Nov.  i,  1908,  p.  23. 
tGood  Roads  Magazine,  April,  1908,  p.  in. 


116 


CHAPTER  VIII. 

RETAINING  WALLS. 

Retaining  walls  are  frequently  required  to  hold  back  an  adjoining  mass  of 
earth  from  sliding  upon  a  highway  or  for  supporting  the  lower  side  of  a  high- 
way on  a  side  hill.  In  fact,  where  the  highway  is  cut  in  the  side  of  a  hill  it 
may  be  necessary  to  use  a  retaining  wall  on  the  up-hill  as  well  as  the  down-hill 
side  of  the  road.  Walls  are  also  necessary  in  many  cases  where  an  embank- 
ment is  confined  to  a  limited  width  as,  for  instance,  where  the  highway  is» 
carried  up  to  and  over  a  railroad  on  an  inclined  embankment  which  is  confined 
on  either  side  of  the  roadway  by  a  wall  running  parallel  with  the  roadway. 


FIG.  58.— RETAINING^ ALLS, AT^DELLWOOD  PARK,"? JOLIET,  ILL. 

Fig.  58  illustrates  a  use  of  retaining  walls  which  is  quite  common.  The 
two  walls  shown  hold  back  the  earth  on  either  side  of  an  inclined  passage  way 
leading  to  the  subway  entrance  in  Dellwood  Park,  near  Joliet,  Illinois.  In  the 
left  of  the  picture  is  a  highway  and  on  the  right  the  park.  These  walls  were 
built  of  concrete  made  of  "ATLAS"  Portland  Cement. 

Retaining  walls  are  needed  in  many  places  in  addition  to  the  uses  already 
cited. 


117 


Concrete  retaining  walls  are  built  either  with  or  without  steel  reinforce- 
ment and  they  have  come  into  prominence  because  they  are  more  economical 
than  the  stone  masonry  walls  so  universally  used  until  a  few  years  ago.  Con- 
crete has  already  demonstrated  its  usefulness  as  a  material  for  wall  construc- 
tion, not  only  because  of  its  low  first  cost,  but  also  because  no  maintenance  is 
necessary.  A  stone  retaining  wall  must  be  pointed  from  time  to  time  to  keep 
the  joints  closed  or  the  masonry  will  soon  be  disintegrated  by  frost.  Concrete 
walls  have  practically  no  joints  and  hence  no  maintenance  charges. 


Type  Cov/7/erforf  Type 

FIG.  59.— TYPES  OF  REINFORCED  CONCRETE  RETAINING  WALLS 

KINDS  OF  RETAINING  WALLS. 

Retaining  walls  are  built  in  the  form  of  thin  reinforced  concrete  walls  or  as 
gravity  walls  of  plain  concrete  containing  little  or  no  steel  reinforcement. 

Gravity  walls  are  designed  to  withstand  the  earth  pressure  behind  them  by 

118 


being  made  sufficiently  heavy  to  prevent  sliding  or  overturning.     They  do  not 
utilize  the  weight  of  the  earth  behind  them  to  add  to  their  strength. 

Reinforced  concrete  walls,  however,  depend  to  a  considerable  extent  on  the 
earth  sustained  to  add  to  their  stability.  The  earth  behind  the  walls  presses 
against  it,  but  at  the  same  time  the  wall  is  of  such  a  shape  that  this  earth  pres- 
sure helps  to  some  extent  to  prevent  sliding  or  overturning.  Reinforced  walls 
can  be  made  much  thinner  than  gravity  walls  and  for  this  reason  reinforced 
walls  are  usually  cheaper. 

Reinforced  walls  as  usually  built  consist  of  a  thin  vertical  wall  attached  to 
a  horizontal  base  and  braced  either  by  counterforts  on  the  back  or  by  but- 


RETAINING  WALLS,  BIRMINGHAM,  ALA. 

tresses  on  the  front  side.  In  more  recent  designs  no  buttresses  or  counterforts 
are  used  and  the  wall  then  is  a  vertical  slab  of  reinforced  concrete  attached  to 
a  horizontal  base. 

Fig.  59  illustrates  the  two  more  usual  types  of  reinforced  concrete  walls, 
cantilever  and  counterfort  types. 

Buttresses  projecting  out  in  front  of  the  wall  are  not  often  used,  for  they 
take  up  too  much  space  which  in  many  cases  must  be  utilized  for  other  pur- 
poses. In  addition  they  give  a  very  unsightly  appearance  to  the  face  of  the 
wall. 

Counterforts  are  thin  walls  running  back  into  the  earth  behind  and  serve  to 


119 


brace  the  main  vertical  wall.  They  are  quite  frequently  used,  but  the  inverted 
T-shaped  cantilever  type  is  so  much  more  easily  and  cheaply  constructed  that 
it  should  be  used  unless  the  wall  is  at  least  18  feet  high  above  ground,  in  which 
case  the  counterfort  type  may  be  more  economical.  Counterforts  rest  on  and 
are  connected  to  the  horizontal  base  of  the  wall,  and,  being  reinforced  with 
steel  bars,  they  really  act  as  ties  on  the  back  of  the  wall. 

GRAVITY  RETAINING  WALLS. 

With  a  gravity  type  of  construction,  the  weight  of  the  wall  is  relied  upon 


BEAM  BRIDGE  ON  PRIVATE  ESTATE,  REDLANDS,  CAL. 

to  sustain  the  earth  pressure  and  the  wall  must  not  only  be  of  sufficient  weight 
but  also  must  have  the  proper  shape. 

In  the  construction  of  retaining  walls  of  any  shape  or  kind,  care  must  be 
taken  to  get  good  foundations.  If  the  material  under  the  wall  is  compact 
sand  or  gravel,  there  should  be  no  trouble  with  the  foundation.  In  some  cases, 
where  it  is  necessary  to  build  a  wall  on  rather  soft  ground,  the  sub-soil  must  be 
thoroughly  drained  and  in  addition  it  must  be  compacted  by  ramming  sand  or 
gravel  or  stone  into  it.  Where  the  soil  is  very  soft,  piles  are  required  to  sustain 
the  weight  of  the  wall  with  the  earth  pressure  behind  it.  In  building  walls 
upon  rock  which  has  an  inclined  surface,  this  surface  must  be  made  horizontal, 
stepped,  or  roughened  by  blasting  to  prevent  the  wall  from  sliding  down  the 

120 


inclined  rock  surface.  Several  large  retaining  walls  have  failed  because  this 
was  not  regarded.  By  taking  the  precautions  just  mentioned  no  trouble  will 
be  experienced. 

Gravity  walls  are  usually  made  with  a  coping  on  top  of  the  main  body  of 
the  wall.  The  front  or  exposed  face  of  the  wall  is  sometimes  made  vertical 
and  is  sometimes  given  a  batter,  that  is  slightly  inclined,  and  the  back  side  of 
the  gravity  wall  is  either  sloped  or  stepped  so  that  the  base  of  the  wall  is 
thicker  than  the  top.  A  slight  batter  on  the  face  adds  to  the  appearance  of  the 
construction,  but  too  large  a  batter  makes  the  wall  look  as  if  it  were  leaning 
backwards.  For  low  walls,  say  those  under  12  or  15  feet  in  height,  the  face 
may  be  made  vertical,  although  a  batter  of  y^  inch  per  foot  while  not  abso- 
lutely necessary  is  desirable.  In  heavy  construction  this  batter  is  sometimes 
exceeded,  but  should  never  be  more  than  1^2  inches  per  foot. 


COPINGS. 

The  coping  for  a  gravity  wall  should  overhang  the  front  surface  of  the  wall 
2  or  3  inches  and  should  be  from  12  to  18  inches  deep,  depending  on  the  height 
of  the  wall.  For  heights  of  less  than  15  feet  a  coping  12  inches  deep  should  be 
used,  while  for  walls  of  greater  heights  the  coping  should  be  15  to  18  inches 
deep. 

The  top  surface  of  the  coping  should  be  sloped  backward  so  that  dirt  will 
not  be  washed  towards  the  front  edge  of  the  coping  and  thus  will  not  drop  on 
the  front  face  of  the  wall  and  discolor  it.  The  back  edge  of  the  top  surface 
should  be  J4  inch  below  the  front  edge.  The  front  surface  of  the  coping  should 
be  vertical  and  the  back  is  sometimes,  though  not  always,  made  so.  The  two 
upper  corners  and  the  front  lower  corner  should  be  beveled  off  so  that  there 
will  be  no  sharp  corners  of  concrete  exposed.  This  beveling  can  be  best  done 
by  nailing  in  the  forms  strips  of  molding  having  triangular  cross  sections. 

Copings  may  be  laid  on  top  of  the  wall  after  the  concrete  in  the  wall  is 
hardened  or  they  may  be  laid  at  the  same  time  as  the  body  of  the  wall.  The 
top  and  front  surface  of  the  coping  to  a  depth  of  2  inches  may  be  made  of  a 
mortar  of  i  part  "ATLAS"  Portland  cement  and  2  parts  clean  sand  laid  be- 
tween the  forms  and  the  inner  body  of  the  concrete.  In  no  case  should  the 
mortar  be  plastered  on  the  concrete  after  the  latter  has  hardened.  The  upper 
surface  of  the  coping  should  be  "floated'  or  finished  in  the  same  manner  as  is 
the  wearing  surface  of  side  walls. 

Copings  should  be  laid  with  vertical  joints  to  match  the  vertical  joints  in 
the  body  of  the  retaining  wall. 


121 


FORMS  FOR  GRAVITY  WALLS. 

In  Fig.  60  is  shown  a  good  arrangement  for  the  construction  of  forms  for  a 
gravity  wall  and  a  movable  form*  for  building  the  coping  in  sections  12  feet 
long  is  likewise  shown  in  the  same  figure. 


of 

Cop/ng 
frame. 


FIG.  60.— FORMS  FOR  GRAVITY  RETAINING  WALL 


The  forms  for  the  wall  consist  of  sheeting  made  of  1^2  or  2-inch  lumber 
braced  by  2  by  4-inch  studs  and  2  by  4-inch  inclined  struts  spiked  to  a  post 
driven  in  the  ground.  The  front  and  back  forms  are  separated  by  means  of  2 
by  4-inch  braces  or  by  ^-inch  bolts  running  through  both  of  them  and  also 
through  a  piece  of  i  or  i^-inch  pipe  between  them,  these  pipes  serving  as 
spacers  for  the  two  forms  as  well.  Wires  are  sometimes  used  in  place  of  the 
bolts,  but  they  are  apt  to  stretch  or  break  and  bolts  are  better. 

In  placing  concrete  in  the  forms,  care  must  be  taken  to  avoid  any  longitu- 
dinal joints  on  the  front  face  of  the  wall.  To  this  end  the  wall  should  be  divided 
into  short  sections  such  that  the  work  in  one  section  can  be  completed  without 
leaving  any  horizontal  joints.  Of  course  in  such  an  arrangement  the  forms 
have  to  be  planked  up  at  the  outer  end  of  the  section,  these  end  boards  being 
removed  when  the  adjoining  section  is  begun. 


""'Engineering  News/'  Vol.  L.,  July  9,  1903,  p.  37. 

122 


The  movable  form  shown  in  Fig.  60  is  useful  where  the  coping  is  built  after 
the  body  of  the  wall.  These  forms  are  made  in  sections  12  feet  in  length  with 
3  of  the  bracing  frames,  one  at  each  end  and  one  in  the  middle  of  the  1 2-foot 
section.  They  are  held  in  place  on  top  of  the  wall  and  the  coping  concrete  is 
deposited  within  the  form  and  after  the  concrete  has  set  the  bolts  at  the  points 
shown  are  removed  so  that  the  forms  can  be  taken  off. 


DIMENSIONS  OF  GRAVITY  WALLS. 

The  accompanying  table  shows  dimensions  and  quantities  of  concrete  for 
gravity  walls  shown  in  Fig.  60,  with  heights  varying  from  6  feet  to  20  feet,  the 
heights  being  the  difference  in  elevation  between  the  upper  and  lower  levels  of 
the  earth. 


DIMENSIONS  AND  QUANTITIES  OF  GRAVITY  RETAINING  WALLS 


Height 

Above  Ground 
Level, 
Feet 

Width  of  Base 

Total  Height         Batter  on  Face        Crete    in8  Wall' 
Feet                        Inches                  1  FoQt  ^^ 

6                     2  ft.      3  in.                       10                            4  ^ 

0.64 

8                     3 

0 

12                            5  ^ 

0.92 

10                     3 

9 

14                            Qy2 

1.26 

12                     4 

6 

16                            7  ^ 

1.65 

14                     5 

3 

is                   ay2 

2.10 

16                     6 

0 

20                            9^ 

2.61 

18 

6 

9 

22                          10  }4 

3.17 

20 

7 

6 

24                          11  ^ 

3.78 

The  bottom  of  the  wall  should  in  all  cases  go  well  below  the  frost  line. 
Four  feet  has  been  taken  in  this  case,  though  of  course  this  will  vary  with  dif- 
ferent localities.  Four  feet,  however,  is  usually  enough,  even  in  the  coldest 
climates.  The  coping  is  shown  12  inches  high  and  18  inches  wide  on  top  and 
the  top  surface  should  have  at  least  a  ^-inch  slope  towards  the  back. 

The  width  of  the  base  must  of  course  be  made  larger  as  the  height  of  the 
wall  increases.  For  highway  work  where  the  upper  surface  of  the  ground  is 
horizontal  and  level  with  the  top  of  the  wall  it  is  customary  to  make  the  base 
%  of  the  height  of  the  wall,  the  height  being  taken  as  the  distance  between  the 
upper  and  lower  levels  of  the  ground,  thus :  if  the  height  of  the  wall  is  20  feet 
the  base  would  be  %  of  20,  that  is  7^  feet.  The  batter  on  the  front  face  is  YZ 
inch  per  foot  of  vertical  distance  under  the  coping,  that  is,  y^  times  23  or  11^2 
inches.  In  this  case  the  amount  in  i  foot  length  of  wall  is  3.78  cubic  yards. 

123 


Where  the  earth  to  be  sustained  is  rather  wet  and  slopes  up  from  the  top  of 
the  wall  instead  of  being  horizontal,  the  thickness  of  the  base  should  be  */2  of 
the  height  of  the  wall. 


FIG.  61.— SECTIONS  FOR  REINFORCED  RETAINING  WALLS. 

REINFORCED   RETAINING  WALLS. 

The  cantilever  retaining  walls  shown  in  Fig.  61  consist  of  a  vertical  slab 
of  reinforced  concrete  attached  to  a  reinforced  concrete  base,  the  whole  sec- 
tion being  really  an  inverted  T.  The  figure  shows  designs  for  2  walls,  one 
for  a  total  height  of  8  feet,  the  other  12  feet.  In  severe  climates  the  bottom 
of  these  walls  should  be  placed  4  feet  below  the  surface  of  the  ground  in  front 
of  them,  thus  making  the  visible  height  of  the  finished  wall  4  feet  and  6  feet 
respectively.  Maximum  pressure  on  soil  from  these  walls  is  2  tons  per  sq.  ft. 


124 


Great  care  must  be  taken  to  place  the  steel  reinforcement  in  the  exact 
positions  called  for  by  the  drawing.  In  each  wall  the  reinforcement  consists 
of  5  sets  of  reinforcing  bars.  In  the  base  of  the  1 2-foot  wall  there  is  one  set 
of  horizontal  half-inch  round  bars  spaced  4  inches  apart  and  i^  inches  above 
the  lower  edge  of  the  base.  Near  the  upper  surface  of  the  base  there  is  a  set 
of  54-inch  round  rods  spaced  4^4  inches  apart  and  slightly  inclined  as  shown 
in  the  drawing.  In  the  vertical  parts  of  the  wall  there  are  two  sets  of  54-inch 
round  horizontal  rods,  one  set  near  the  front  face  and  one  near  the  rear  face  of 
the  wall.  Also  in  the  vertical  part  there  is  a  set  of  f^-inch  round  vertical  rods 


ARCH  IN  PHILLIPS  PARK,  AURORA,  ILL. 


near  the  back  of  the  wall.  These  vertical  rods  must  be  imbedded  in  the  base 
as  shown.  In  this  set  of  vertical  rods  every  fifth  rod  should  extend  from  the 
bottom  to  the  top  of  the  wall,  these  rods  being  17  inches  apart.  Then  midway 
between  each  pair  of  these  long  rods  a  shorter  rod  extends  from  the  bottom  of 
the  wall  2/3  of  the  way  to  the  top,  making  the  rods  in  the  middle  third  of  the 
height  S%  inches  apart.  In  the  lower  third  of  the  height  there  are  in  addi- 
tion to  the  rods  mentioned  short  rods  running  from  the  base  up  1/3  of  the 
height  of  the  wall,  thus  making  the  rods  in  this  lower  third  4%  inches  c.  to  c. 
Although  5/s-inch  round  rods  are  shown  in  the  figure,  other  bars  having 
the  same  cross  sectional  area  can  be  used  instead. 

125 


PROPORTIONS  OF  CONCRETE. 

For  gravity  walls  similar  to  those  described  in  this  chapter  for  the  body  of 
the  wall  and  for  the  body  of  the  coping  the  concrete  should  be  mixed  i  part 
"ATLAS'  Portland  Cement,  3  parts  sand  and  6  parts  broken  stone  or  gravel. 
For  the  upper  and  front  surfaces  of  the  coping  a  2-inch  veneer  of  mortar 
mixed  i  part  "ATLAS"  Portland  Cement  and  2  parts  sand  may  be  used,  built 
on  a  part  of  the  coping  at  the  same  time  that  the  concrete  is  placed.  For  a 
gravity  wall  having  a  height  of  more  than  12  feet  "one-man"  stones  may  be 


BEAM  BRIDGE,  SUDBURY,  MASS. 

imbedded  in  the  concrete  as  indicated  in  Chapter  I  under  the  head  of  Rubble 
Concrete. 

For  reinforced  concrete  walls  similar  to  those  described  in  this  chapter 
concrete  should  be  mixed  i  part  "ATLAS"  Portland  Cement,  2^  parts  sand 
and  5  parts  broken  stone  or  gravel. 

In  depositing  the  concrete  against  the  forms,  care  must  be  taken  to  pre- 
vent the  larger  stones  from  collecting  in  pockets  against  the  forms  and  thus 
making  voids  which  will  show  when  the  forms  are  removed. 


126 


EXPANSION  JOINTS. 

When  concrete  is  subjected  to  changes  in  temperature  it  will  expand  or 
contract.  Therefore,  in  long  retaining  walls  vertical  cracks  will  form  in  the 
concrete  unless  the  wall  is  either  reinforced  with  steel  or  vertical  joints  are 
made  at  frequent  intervals.  For  plain  concrete  walls  vertical  joints  should 
be  left  at  intervals  not  exceeding  30  feet ;  these  joints  allowing  the  sections  of 
concrete  to  expand  or  contract  without  forming  unsightly  cracks  in  the  face 
of  the  wall.  While  30  feet  is  the  maximum  distance  between  expansion  joints 
in  plain  concrete  walls,  20  feet  is  the  proper  distance,  and  walls  provided  with 
joints  20  feet  apart  will  not  crack.  Frequently  these  joints  are  run  straight 
through  the  wall  from  front  to  back.  It  is  better,  however,  to  have  the  two 
adjacent  sections  of  the  wall  tongued-and-grooved  or  V-shaped  in  plan. 

DRAINAGE. 

Unless  provision  is  made  for  removing  the  water,  it  will  in  most  cases  collect 
behind  the  retaining  wall  and  considerably  increase  the  pressure  on  the  back 
of  the  wall.  With  clayey  soils  or  other  material  of  similar  nature,  some  pro- 
vision must  be  made  for  removing  this  water  by  drainage.  If  the  wall  is^ 
short,  a  broken  stone  drain  laid  lengthwise  behind  the  wall  and  properly 
graded  so  that  the  water  will  flow  along  the  back  and  then  away  from  the 
wall  will  serve  every  purpose.  In  the  case  of  long  walls,  drainage  holes  must 
be  placed  through  the  wall  so  that  the  water  may  pass  from  the  back  to  the 
front  where  it  can  be  drained  off.  These  drainage  holes  can  be  made  by  plac- 
ing cement  or  clay  tile  pipes  3  or  4  inches  in  diameter  in  the  concrete,  sloping 
downward  toward  the  front  of  the  wall.  Wooden  forms  of  i-inch  planks 
can  be  used  to  make  a  square  hole,  but  the  planks  are  hard  to  remove  after 
concreting.  The  outlet  in  the  front  face  should  be  6  inches  above  the  surface 
on  the  ground  in  front  of  the  wall.  Two  or  three  barrow  loads  of  cobble 
stones  and  gravel  should  be  placed  at  the  upper  end  where  the  pipe  pierces 
the  back  surface  of  the  wall. 

In  very  wet  soils  loose  stones  10  to  15  inches  in  thickness  should  be  piled 
up  against  the  back  of  the  wall  from  the  bottom  to  within  2  feet  of  the  top. 
This  arrangement  together  with  the  weep  holes  just  described  will  afford  per- 
fect drainage  even  in  very  wet  material. 

Weep  holes  should  be  placed  from  10  to  20  feet  apart  lengthwise  of  the 
wall,  depending  on  the  nature  of  the  soil.  They  should  be  placed  10  feet  apart 
in  wet  ground. 


127 


CHAPTER  IX. 
MISCELLANEOUS. 

FENCE  POSTS. 

Reinforced  concrete  fence  posts  are  better  than  wooden  ones  because  they 
will  not  decay,  are  more  uniform  in  size  and  shape,  and  in  the  long  run  are 
cheaper.  Fence  posts  of  wood  are  cheaper  in  first  cost  than  those  made  of 
concrete,  but  ordinary  wooden  posts  decay  in  a  comparatively  short  time 
while  concrete  construction  lasts  indefinitely.  Cast  iron  posts  last  very  well, 
but  their  cost  prohibits  their  use  except  in  a  few  cases.  Concrete  posts  prop- 
erly reinforced  with  steel  rods  possess  the  necessary  strength  and  durability 
and  at  the  same  time  may  be  obtained  in  any  locality  at  a  reasonable  cost. 


FIG.  62.— FORMS  FOR  CONCRETE  FENCE  POSTS. 

Fence  posts  for  farms  and  for  division  fences  in  city  suburbs  should  gen- 
erally be  7  feet  long,  6  inches  square  at  the  lower  and  4  inches  square  at  the 
upper  end.  These  posts  are  usually  made  to  support  wire  fences. 

For  fences  adjoining  streets  in  towns  the  posts  should  be  from  5  to  6  feet 
in  length  with  ends  the  same  size  as  for  farm  posts.  These  posts  carry  wire 

128 


fences  or  wooden  fences.  If  a  wooden  fence  is  supported  by  concrete  posts 
the  street  side  of  the  posts  should  be  set  vertical,  the  lower  wooden  stringer 
of  the  fence  being  bolted  to  the  front  vertical  face  of  the  post  and  the  upper 
stringer  bolted  on  top  of  the  post. 

A  form  for  making  an  individual  post  is  shown  in  Fig.  62  and  consists  of 
a  base  board  1*4  inches  thick  and  12  inches  wide.  Upon  this  are  set  two  bev- 
eled pieces  of  2-inch  lumber  6  inches  wide  at  one  end  and  4  inches  wide  at  the 
other.  The  two  side  boards,  connected  with  2  or  3  cross  braces  on  top,  are  set 
against,  but  not  nailed  to,  the  two  small  strips,  the  latter  being  nailed  to  the 
base  board.  The  blocks  at  the  ends  are  nailed  in  place. 


FIG.  63.— MULTIPLE  FORM  FOR  CONCRETE  FENCE  POSTS. 


Short  pieces  of  I/2-inch  greased  round  rods  should  be  placed  through  the 
side  boards  before  the  concrete  is  placed  in  the  forms  and  allowed  to  remain 
four  or  five  hours  till  the  concrete  is  hardened  enough  so  that  they  can  be 
pulled  out.  The  fence  wires  can  be  run  through  these  holes  or  can  be  run  in 
front  of  the  post  and  tied  to  the  same  with  No.  12  or  14  galvanized  wire. 
These  holes  for  fence  wires  do  not  decrease  the  strength  of  the  post  and  afford 
a  better  method  of  attachment  than  staples  placed  in  the  front  surface  of  the 
post.  If  staples  are  used  they  must  be  galvanized. 

129 


With  the  form  in  place,  concrete,  made  one  part  "ATLAS"  Portland 
Cement,  two  parts  clean  coarse  sand,  and  four  parts  broken  stone  or  screened 
gravel  of  about  one  inch  diameter  particles,  should  be  placed  in  the  form  and 
tamped  to  a  thickness  of  one  inch.  Then  two  pieces  of  wire  about  3/16  inch 
in  diameter  and  6%  feet  long  are  placed  on  the  layer  of  concrete,  each  one  inch 
from  the  side  forms.  Another  layer  of  concrete  must  then  be  tamped  on  the 
first  layer  until  the  concrete  is  within  one  inch  of  the  top  edge  of  the  side 
forms  and  two  more  wires  like  the  first  ones  then  laid  and  the  forms  filled 
with  concrete.  After  the  concrete  is  tamped  and  smoothed  off  on  the  upper 
surface,  the  post  is  set  aside  and  allowed  to  lie  ten  or  twelve  hours  before  the 
side  forms  are  removed.  The  base  board  must  be  left  in  place  ten  days 
during  which  time  the  post  must  be  sprinkled  daily  and  must  not  be  disturbed. 
After  this  time  the  posts  should  be  allowed  to  harden  for  four  weeks  more 
before  being  used. 

Fig.  63  shows  a  mold  for  casting  four  posts  at  a  time.  The  boards  sep- 
arating the  posts  are  slipped  in  between  cleats  at  each  end  and  are  either 
screwed  to  the  end  pieces  or  held  in  place  by  tightening  up  the  wedges  at 
the  ends.  Wedges  bearing  against  blocks  nailed  to  the  base  board  prevent 
the  side  boards  from  spreading.  Staples  pressed  in  the  upper  face  of  the  con- 
crete before  the  concrete  sets  afford  an  easy  connection  for  the  fence  wires. 

Forms  should  be  made  of  dressed  lumber  and  should  be  oiled  or  greased 
with  soft  soap  before  using. 

Fence  posts  such  as  here  described  should  cost  from  thirty  to  fifty  cents 
each. 

Corner  posts  must  be  larger  than  the  side  posts,  10  by  10  inches  at  the 
base  and  10  by  10  inches  at  the  top,  and  9  feet  long  being  good  dimensions. 
Use  four  3^-inch  round  rods  for  reinforcement  of  3/1 6-inch. 

CONCRETE  FENCE  POSTS  AT  DELLWOOD  PARK. 

In  Fig.  64  are  shown  some  concrete  fence  posts  around  Dellwood  Park, 
four  miles  from  Joliet,  111.  This  fence*  encloses  a  tract  of  land  approximately 
1,320  feet  wide  by  2,200  feet  long  and  has  1,500  concrete  posts  varying  in 
length  from  7  to  9  feet.  At  the  top  the  posts  are  4  inches  square  and  at  the 
bottom  they  are  4  by  6  inches  in  cross  section.  The  concrete  was  made  one 
part  "ATLAS"  Portland  Cement  and  one  part  stone  screenings  passing  a 
^i-inch  screen.  The  reinforcement  consists  of  four  rods,  one  in  each  corner. 

The  forms  used  were  similar  to  the  single  form  shown  in  Fig.  62  and  were 
left  on  the  posts  twenty-four  hours,  the  side  boards  being  removed  after  this 
period.  The  posts  were  then  left  for  an  additional  twenty-four  hours  lying 

*Engineering  Record,  Vol.  55,  March  23,  1907,  page  377. 

130 


on  the  base  boards  after  which  the  bases  together  with  the  post  were  moved 
to  a  platform  where  they  remained  a  week.  They  were  then  laid  out  to 
harden  till  used,  being  kept  wet  for  the  first  three  weeks  after  they  were 
made.  Two  men,  each  paid  $2  per  day,  could  make  about  forty  posts  in 
one  day.  The  cement  cost  $2  per  barrel,  the  reinforcement  3^2  cents  per 
pound  and  the  screenings  75  cents  per  cubic  yard.  The  posts,  9  feet  long, 
cost  65  cents  each,  a  rather  high  cost  because  of  the  design  and  the  richness 
of  the  proportions.  Posts  at  angles  of  the  fence  were  heavier  than  the  others 
and  were  braced. 


FIG.  64.— CONCRETE  POSTS  AT  DELL  WOOD  PARK.SJOLIET,  ILL. 


HITCHING   POSTS. 

Concrete  hitching  posts  without  reinforcement  do  not  have  sufficient 
strength.  They  must  be  reinforced  with  a  ^g-inch  diameter  rod  imbedded  in 
each  corner.  Hitching  posts  should  be  set  at  least  2^2  feet  in  the  ground  if 
they  are  surrounded  by  a  concrete  sidewalk.  If  set  in  earth  without  the 
surrounding  walk  they  should  be  placed  3  feet  in  the  ground.  The  outer 
surface  must  be  at  least  6  inches,  or  still  better,  8  inches  from  the  edge  of  the 
curb. 

Posts  similar  to  that  shown  at  the  left  side  of  Fig.  65  are  made  in  the  same 


manner  as  fence  posts  except  that  there  is  a  2-inch  ring  attached  to  a  staple  in 
the  top. 

The  post  shown  in  the  right  half  of  Fig.  65  is  neat  but  is  more  difficult  to 
make  than  the  plain  post.  The  depressed  surfaces  on  the  sides  are  one-half 
inch  deep  and  are  best  formed  by  nailing  one-half-inch  wooden  pieces  to  the 
inside  of  the  forms.  Tamp  the  concrete  into  the  corners  of  the  molds  well 
and  after  the  forms  are  removed  give  the  surfaces  of  the  posts  a  coating  of 
cement  mixed  with  water,  applied  with  a  brush. 


/-  £  "/rtotfJ&6'/p  /'/?  eoc/?  earner      /-  f  /?od  6&O  "/$  //?  e&c/7  ccrrser 

FIG.  65.—CONCRETE  HITCHING  POSTS. 

LAMP  POSTS. 

Concrete  is  being  used  for  lamp  posts  to  support  electric  lights  in  parks 
and  other  similar  places.  These  posts  are  usually  about  20  to  24  feet  in 
length  and  are  set  5  or  6  feet  into  the  ground.  They  should  be  6  or  8  inches 
in  diameter  at  the  bottom  and  4  or  5  inches  at  the  top,  the  larger  diameters 
being  required  for  the  highest  posts.  A  piece  of  i-inch  gas  pipe  is  placed  in 
the  center  of  the  post  throughout  its  length  to  carry  the  wires  from  the  lamp 
to  the  bottom  of  the  post  where  the  wires  then  connect  with  the  underground 

132    - 


electric  system.  The  lamp  can  be  set  directly  on  top  of  the  post  or  it  can  be 
suspended  from  the  outer  end  of  a  curved  pipe  which  is  connected  to  the  pipe 
passing  down  through  the  post.  The  methods  of  construction  are  similar  to 
those  used  in  making  fence  posts. 

One  rod  one-half  inch  in  diameter  in  each  corner  of  a  square  post  is  suffi- 
cient for  reinforcement.  A  square  post  with  beveled  edges  is  simpler  to  make 
than  a  round  post,  but  is  not  quite  so  neat  in  appearance. 


k^BRIDGEIAND  DRINKING  FOUNTAIN,  LINCOLN  PARK,  CHICAGO,  ILL. 


DRINKING   FOUNTAINS. 

Drinking  fountains  of  concrete  are  giving  good  satisfaction  in  parks  even 
where  the  climate  is  severe.  These  fountains  are  generally  made  with  a 
circular  base  about  3  feet  in  diameter  and  a  circular  stem  and  bowl  on  top; 
the  stem  gradually  diminishing  in  diameter  from  the  base  and  then  enlarging 
into  the  bowl  which  is  from  3^/2  to  4  feet  in  diameter. 

Reinforcement  must  be  used  in  fountains  to  give  them  sufficient  strength 
to  withstand  shocks.  Wire  mesh  of  any  kind  bent  to  shape  and  imbedded  in 
the  concrete  is  all  that  is  necessary. 

The  concrete  must  be  mixed  quite  wet,  about  the  consistency  of  thick 
cream  and  in  the  proportions  of  i  part  "ATLAS"  Portland  Cement,  i^  parts 

133 


clean,  coarse  sand,  and  3  parts  broken  stone  or  screened  gravel  of  about  i  inch 
diameter. 

The  bowl  must  be  cast  at  one  operation  and  as  quickly  as  possible  so  that 
it  will  be  water  tight. 

Good  drinking  fountains  of  this  kind  have  been  built  for  $12  with  $5  for 
the  setting. 


BRIDGE  WITH  OPEN  SPANDRELS,  CHICAGO,  ILL. 


134 


BRIDGE  AT  HAWORTH,  N.  J. 


PARKWAY  BRIDGE,  MEDFORD,  MASS. 
135 


136 


CONCRETE 

IN 

RAILROAD 
CONSTRUCTION 


A    TREATISE    ON    CONCRETE 

FOR 
RAILROAD    ENGINEERS    AND    CONTRACTORS 


PRICE,  $1.00 


PUBLISHED    BY 

THE    ATLAS    PORTLAND    CEMENT    COMPANY 

30    BROAD    STREET 

NEW    YORK 


Copyrighted     1909 

by 

THE    ATLAS    PORTLAND    CEMENT    Co. 
30     Broad    St.,     N.     Y. 


All    rights    reserved 


CONTENTS 


PREFACE. 
INTRODUCTION. 

CHAPTER  I. — RAILROAD  CONSTRUCTION.  Page 

Cost 11 

Safety 12 

Durability 12 

Freedom  from  Vibration 12 

Fire  Resistance 12 

Versatility  of  Design 13 

Water  Tightness 13 

Alterations 13 

Strengthening  Old  Masonry 13 

Foundations 13 

CHAPTER  II. — DESIGN  AND  CONSTRUCTION. 

Cement 15 

Sand 15 

Fine  Aggregate 15 

Broken  Stone  and  Gravel 16 

Coarse  Aggregate 16 

Steel 16 

Proportions 18 

Mixing 18 

Consistency 19 

Placing 19 

Joints 20 

Surfaces. 20 

Forms. .  20 


Page 

Waterproofing 20 

Design  of  Plain  Concrete 21 

Bending  Moments 21 

Design  of  Reinforced  Concrete 22 

Working  Stresses 23 

CHAPTER  III. — BRIDGES. 

Arch  Bridges 28 

Solid  Filled  Spandrels 28 

Skeleton  Spandrel  Construction 28 

Expansion  Joints 30 

Waterproofing 30 

Jackson  Street  Arch,  C.  R.  R.  of  N.  J 30 

Paulins  Kill  Viaduct,  D.,  L.  &  W.  R.  R 34 

Vermillion  River  Bridge,  C.,  C.,  C.  &  St.  L.  Ry 36 

Wallkill  River  Viaduct,  E.  &  J.  R.  R 38 

Girder  Bridges 39 

C.,  B.  &  Q.  R.  R.  Track  Elevation  Work 41 

Through  Girder  Bridge,  C.,  B.  &  Q.  R.  R .'.  .  45 

Trestles : 45 

Richmond  Viaduct  of  the  Richmond  &  Chesapeake  Bay  Railway 45 

Concrete  Pile  Trestles,  C.,  B.,  &  Q.  R.  R 51 

Concrete  Pier  Trestles,  C.,  B.  &  Q.  R.  R 53 

Overhead  Railway  Bridges 54 

Overhead  Highway  Bridge  No.  19.31,  D.,  L.  &  W.  R.  R  .  .  .  .  . 54 

.  First  Avenue  Viaduct,  L.  I.  R.  R 57 

Bridge  Floors 60 

Bridge  Floors,  C.,  B.  &  Q.  R.  R 61 

Reinforced  Concrete  Bridge  Floors,  D.,  L.  &  W.  R.  R 62 

CHAPTER  IV. — CULVERTS 

Table  of  Data  for  4  to  20-Foot  Span  Culverts 67 

Example  of  Culvert  Construction 68 

Standard  Pipe  Culverts,  N.  Y.  C.  &  H.  R.   R.  R " 68 

Standard  3-Foot  Arch  Culvert,  D.,  L.  &  W.  R.  R 69 

Indian  Creek  Culvert,  K.  C.,  M.  &  O.  Ry 69 

Eighteen-Foot  Arch  Culvert,  Bangor  &  Aroostook  R.  R 73 

Thirty-Foot  Culvert,   C.,   M.   &  St.   P.    Ry 75 

Horse  Shoe  Culvert. .              ....            75 


CHAPTER  V.- — PIERS  AND  ABUTMENTS. 

Piers 77 

Standard  Piers,  N.  Y.  C.  &  H.  R.  R.  R 78 

Raising  Grade  of  Old  Masonry  Piers 79 

Reinforced  Piers,  K.  C. ,  M.  &  O.  Ry 80 

Abutments 81 

Plain  Abutments 81 

Reinforced  Abutments 81 

Van  Cortlandt  Ave.  Abutments,  N.  Y.  C.  &  H.  R.  R.  R 81 

Third  Street  Abutments,  K.  C.,  M.  &  O.  Ry.".  84 


CHAPTER  -VI. — RETAINING  WALLS. 

Table  for  Design  of  T-Type  Retaining  Walls 89 

Table  for  Design  of  Counterfort-Type  Retaining  Wall 91 

Examples  of  Retaining  Walls 93 

Standard  Gravity  Retaining  Wall,  N.  Y.  C.  &  H.  R.  R.  R 93 

Reinforced  Retaining  Walls,  C.,  B.  &  Q.  R.  R 94 

Reinforced  Buttress  Retaining  Walls,  D.,  L.  &  W.  R.  R 97 


CHAPTER  VII. — STATIONS,  TRAIN  SHEDS  AND  PLATFORMS. 

Scarsdale  Station,  N.  Y.  C.  &  H.  R.  R.  R 99 

Marathon  Station,  D.,  L.  &  W.  R.  R 101 

O'Fallon  Station,  Wabash  R.  R 101 

Trainsheds 103 

Hoboken  Terminal  Train  Shed,  D.,  L.  &  W.  R.  R 103 

Platforms 105 

Standard  Concrete  Platforms  at  Stations,  N.  Y.  C.  &  H.  R.  R.  R.  .  .  .  105 

Station  Platforms,  B.  R.  T.  Co 106 

Electric  Zone  Standard  Platforms,  N.  Y.  C.  &  H.  R.  R.  R.  109 


CHAPTER  VIII. — COAL  AND  SAND  STATIONS  AND  ASH-HANDLING  PLANTS. 

Concord  Coal  and  Sand  Station,  N.  &  W.  Ry 112 

Ash-Handling  Plants 115 

Hoboken  Coal  Trestle,  D.,  L.  &  W.  R.  R.  .  ...    117 


Page 
CHAPTER  IX. — ROUNDHOUSES  AND  TURNTABLE  PITS. 

Roundhouses 121 

Foundations  and  Pits 121 

Roof 121 

Supporting  Columns 121 

Outer  Walls 121 

Table  Showing  Comparison  of  Cost  of  Different  Types  of  Roundhouses .  .  122 

Costs 123 

Waterbury  Roundhouse,  N.  Y.,  N.  H.  &  H.  R.  R 123 

Turntable  Pits 127 

Standard  Pit,  N.  Y.  C.  &  H.  R.  R.  R 127 


CHAPTER  X. — SIGNAL  TOWERS,  WATER  TANK  SUPPORTS  AND  BUMPING  POSTS. 

Signal  Towers 129 

Naugatuck  Tower,  N.  Y.,  N.  H.  &  H.  R.  R 129 

Kings  Bridge  Tower,  N.  Y.  C.  &  H.  R.  R.  R 131 

Grove  Street  Signal  Tower,  D.,  L.  &  W.  R.  R 132 

Water  Tank  Supports 135 

Water  Tank  Support  at  Waterbury,  N.  Y.,  N.  H.  &  H.  R.  R 135 

Bumping  Posts 138 

Standard  Concrete  Bumping  Posts,  D.,  L.  &  W.  R.  R 138 


CHAPTER  XL — POWER  STATIONS,  SHOPS,  WAREHOUSES  AND  GRAIN  ELEVATORS. 

Power  Stations 141 

Cos  Cob  Power  Plant,  N.  Y.,  N.  H.  &  H.  R.  R 141 

Shops  and  Warehouses 146 

N.  O.  &  G.  N.  R.  R.  Shop  and  Store  House,  Bogalusa,  La 146 

Mott  Haven  Car  Shops,  N.  Y.  C.  &  H.  R.  R 147 

Newark  Warehouse,  C.  R.  R.  of  N.  J 148 

Port  Morris  Boiler  House,  D.,  L.  &  W.  R.  R 149 

Loading  Platform,  Sioux  City,  la 149 

Grain  Elevators. .            151 


CHAPTER  XII. — STORAGE  RESERVOIRS. 

Cos  Cob  Storage  Reservoir 155 

Pittsburg  Storage  Reservoir 159 


Page 

CHAPTER  XIII. — DOCKS. 

Hoboken  Pier  No.  7,  D.,  L.  &  W.  R.  R 161 

Almirante    Wharf,    Bocas    Del    Toro,    Panama.  .  163 


CHAPTER  XIV. — TUNNELS  AND  TUNNEL  LINING. 

Standard  Tunnel  Sections,  N.  Y.  C.  &  H.  R.  R.  R 168 

Standard  Tunnel  Facade . 173 

New  Bergen  Hill  Tunnel,  D.,  L.  &  W.  R.  R.  .  173 


CHAPTER  XV. — CONCRETE  TIES  AND  ROADBEDS. 

Ties 175 

Concrete  Roadbeds 178 

Roadbed  Construction  of  the  New  Bergen  Hill  Tunnel,  D.,  L.  &  W.  R.  R.  180 


CHAPTER  XVI. — TELEGRAPH  POLES,  POWER  TRANSMISSION  POLES  AND  TOWERS 

Telegraph  Poles 187 

Telegraph  Poles,  P.,  L.  W.  of  P 190 

Tickler  Poles,  N.,  C.  &  St.  L.  Ry 191 

Power  Transmission  Poles  and  Towers 191 

Brownsville  Transmission  Towers.  .  192 


CHAPTER  XVII. — POSTS  AND  FENCES. 

Fence  Posts 196 

Standard  Concrete  Fence  Posts,  N.  Y.  C.  &  H.  R.  R.  R 197 

Dellwood  Park  Fence  Posts,  C.  &  J.  Ry 197 

Concrete  Fence  Posts,   B.   &  O.   R.   R 200 

Mile  Posts 201 

Whistle  Posts 202 

Clearance  Posts 202 

Property  Line  Posts 202 

Fences 204 

Platform  Fences.  .  204 


INTRODUCTION. 

Economy  in  railroad  construction  demands  permanent  structures.  Mate- 
rials must  be  used  therefore  which  as  far  as  possible  are  proof  against  the 
deteriorating  and  destructive  influences  of  the  elements  and  of  vibration,  so 
as  to  resist  corrosion,  decay  and  fire,  and  the  gradual  weakening  due  to  con- 
tinual, severe  and  constantly  growing  service.  At  the  same  time  the  materials 
must  possess  requisite  strength  for  present  and  future  traffic  combined  with 
cheapness  and  facility  of  construction. 

The  advent  of  reinforced  concrete,  possessing  as  it  undoubtedly  does  in  a 
marked  degree  all  these  qualities  combined  with  a  wide  range  of  possible  uses 
and  versatility  of  design,  has  been  of  the  greatest  importance  to  railroad  engi- 
neers. 

To  illustrate  the  best  of  present  day  practice,  The  Atlas  Portland  Cement 
Company  takes  this  opportunity  to  present  to  the  railroad  world  at  large  a 
brief  treatise  on  concrete  in  railroad  construction,  with  a  view  of  giving  a  com- 
prehensive idea  of  the  diversity  of  the  concrete  structures  in  actual  existence 
on  railroad  lines  throughout  the  country  and  of  the  future  possibilities  of  this 
material  in  the  field  of  railroad  engineering. 

Realizing  that  the  treatment  of  this  subject  demanded  the  attention  of  an 
expert  authority  the  work  was  entrusted  to  Mr.  Sanford  E.  Thompson,  M.  Am. 
Soc.  C.  E.,  one  of  the  foremost  concrete  experts  in  the  country.  The  Atlas 
Portland  Cement  Company,  occupying  as  it  does  a  somewhat  unique  position 
among  cement  manufacturers,  with  its  wide  reputation  for  a  thoroughly  uni- 
form and  standard  product,  its  selection  by  the  United  States  government  to 
furnish  4,500,000  barrels  for  use  in  building  the  Panama  Canal,  and  its 
immense  production — over  40,000  barrels  per  day — commends  the  book  to  its 
readers  with  the  hope  that  it  may  prove  a  fitting  sequel  to  the  former  publica- 
tions of  the  company — "Concrete  Construction  About  the  Home  and  on  the 
Farm,"  "Concrete  Cottages,"  "Concrete  Country  Residences,"  "Reinforced 
Concrete  in  Factory  Construction"  and  "Concrete  in  Highway  Construction." 

THE  ATLAS  PORTLAND  CEMENT  COMPANY. 
New  York,  July,  1909. 


PREFACE. 

In  compiling  this  book  it  has  been  the  aim  of  the  author  and  of  the  pub- 
lishers to  cover  as  thoroughly  as  possible  the  entire  field  of  the  uses  of  con- 
crete in  railroad  construction.  Although  it  is  very  fully  illustrated,  the  photo- 
graphs and  drawings  are  presented  not  as  mere  pictures  but  to  illustrate  in 
detail  the  many  points  which  are  continually  occurring  to  the  railroad  officials 
and  their  engineers  and  designers.  With  this  in  view,  typical  structures  of 
nearly  every  class  are  shown,  with  a  short  description  of  the  essential  features 
of  design  and  construction  of  each. 

The  first  chapter  contains  a  brief  review  of  the  qualities  of  concrete  in  com- 
parison with  other  materials  for  railroad  construction  and  this  is  followed  by 
a  chapter  on  design  and  construction  designed  to  serve  as  a  guide  to  the  intel- 
ligent use  of  concrete.  In  the  descriptive  portion  of  the  book,  which  embodies 
fifteen  chapters,  the  following  subjects  have  been  treated:  Bridges,  Culverts, 
Piers  and  Abutments,  Retaining  Walls,  Stations,  Train  Sheds,  Platforms,  Coal 
and  Sand  Stations,  Coal  Trestles,  Ash  Handling  Plants,  Roundhouses,  Turn- 
table Pits,  Signal  Towers,  Water  Tank  Supports,  Bumping  Posts,  Power  Sta- 
tions, Shops,  Warehouses,  Grain  Elevators,  Storage  Reservoirs,  Docks,  Tun- 
nels and  Tunnel  Lining,  Cross  Ties  and  Road  Beds,  Telegraph  Poles,  Trans- 
mission Towers,  Posts  and  Fences.  A  number  of  miscellaneous  illustrations 
of  general  interest  are  shown  at  the  end  of  the  book. 

All  illustrations  have  been  prepared  especially  for  this  book,  the  half-tones 
being  made  from  original  photographs  while  the  drawings  were  reproduced  in 
the  office  of  the  author  from  the  original  plans  furnished  by  the  chief  engineers 
of  the  various  railroads. 

In  certain  cases,  where  none  of  the  designs  of  existing  structures  were  suffi- 
ciently representative  in  character,  special  designs  have  been  prepared. 

The  descriptive  matter  and  drawings  have  been  compiled  under  the  imme- 
diate direction  of  Mr.  Chester  S.  Allen  of  the  author's  engineering  staff.  The 
author  also  acknowledges  the  assistance  of  Prof.  Frank  P.  McKibben  in  re- 
viewing the  original  designs. 

The  text  and  the  drawings  of  each  structure  have  been  referred  to  the  offi- 
cials of  the  railroad  for  their  approval. 

The  Atlas  Portland  Cement  Company,  and  the  undersigned,  desire  to  ex- 
press their  appreciation  of  the  courtesies  extended  by  the  engineers  of  the 
various  railroads  and  by  the  contracting  companies  who  have  so  kindly  fur- 
nished plans  and  data  for  incorporation  into  the  descriptive  chapters  of  this 
book. 

SANFORD  E.  THOMPSON, 

1909.  Newton  Highlands,  Mass. 

10 


CHAPTER   I. 


RAILROAD  CONSTRUCTION. 

While  the  policy  of  European  railroad  engineers  always  has  been  to  build 
permanent  structures,  the  necessity  in  the  past  of  practising  the  strictest  econ- 
omy in  the  original  building  of  many  of  the  railroads  of  this  country  has  led 
American  engineers  to  exactly  the  opposite  course,  and  as  a  result  railroad 
structures  built  not  many  years  ago  were  largely  of  timber;  bridges  were  of 
the  Howe  truss  and  lattice  type,  trestles  of  pile  and  timber  construction,  and 
stations,  roundhouses  and  freight  sheds  veritable  wooden  fire  traps. 

The  increasing  importance  with  the  attendant  increase  of  incomes  of  the 
railroads  and  the  need  for  more  permanent  structures  coupled  with  the  im- 
provements in  iron  manufacture  resulted  in  the  substitution  of  wrought  iron 
structures  in  place  of  the  wood,  and  this  material  in  turn  was  replaced  by  steel. 
But  it  was  soon  found  that  steel  was  by  no  means  perfect,  since  structures 
built  of  it  required  careful  inspection  and  continual  repairs  and  even  then  rust 
and  gases  had  such  a  deteriorating  effect  that  the  life  of  a  steel  bridge  or  build- 
ing would  probably  be  not  over  30  or  40  years. 

In  the  past  few  years  concrete  has  had  a  marvelous  growth,  and  in  railroad 
construction  perhaps  more  than  in  any  other  branch  of  engineering  it  has  been 
universally  adopted  as  a  building  material.  Not  only  is  it  replacing  steel  con- 
struction, but  perhaps  still  more  it  has  taken  the  place  of  stone  and  brick  ma- 
sonry not  only  for  foundations  but  also  for  various  structures  above  ground, 
such  as  retaining  walls,  bridges,  coaling  stations,  signal  towers,  and  in  fact 
many  of  the  smallest  details. 

COST. 

While  the  cost  of  concrete  construction  is  invariably  higher  than  wood,  it 
is  almost  always  considerably  less  than  stone  masonry  and  will  not  greatly,  if 
at  all,  exceed  steel  in  first  cost. 

The  maintenance  costs  of  a  concrete  structure  are  practically  neglible  and 
it  has  been  estimated  that  the  elimination  of  painting  costs  alone  warrants  an 
initial  expenditure  of  from  10  per  cent  to  15  per  cent  over  the  first  cost  of  a 
steel  structure. 

ii 


SAFETY. 

When  well  designed  and  properly  constructed,  a  reinforced  concrete  struc- 
ture will  be  safe  for  all  time,  since  its  strength  increases  with  age,  the  concrete 
growing  harder  and  the  bond  with  the  steel  becoming  stronger. 

In  building  such  a  structure,  it  is  of  the  utmost  importance  that  the  plans 
and  specifications  should  be  followed  absolutely  and  that  work  should  be  en- 
trusted only  to  men  of  undoubted  experience  in  this  line  of  construction. 


DURABILITY. 

While  steel  and  wooden  structures  grow  weaker  from  rust  and  decay  a 
concrete  structure  as  stated  above  grows  stronger  with  time  and  its  life  is 
measured  by  ages  rather  than  years.  In  addition  to  its  natural  permanence, 
such  a  structure  is  proof  against  tornadoes,  high-water,  fire  and  earthquakes. 
A  number  of  concrete  buildings  in  San  Francisco  withstood  the  shock  of  the 
earthquake,  while  those  around  them  of  terra  cotta  brick  and  stone  were  de- 
stroyed. 

FREEDOM  FROM  VIBRATION. 

Concrete  is  especially  adapted  for  railroad  construction  owing  to  the  fact 
that  its  solidity  and  entire  lack  of  joints  render  it  free  from  the  excessive  vibra- 
tions often  experienced  in  steel  structures.  In  riding  over  a  structure  built 
of  concrete  it  is  particularly  pleasing  to  the  passenger  to  note  the  absence  of  the 
familiar  roar  and  the  lurching  of  the  train  which  is  so  often  endured  in  cross- 
ing a  steel  bridge.  Only  where  there  is  direct  contact,  as  in  ties,  is  there  dan- 
ger of  the  jar  disintegrating  the  concrete.  In  such  cases  either  cushions  of 
wood  or  earth  should  be  provided  to  deaden  the  shock,  or  the  concrete  should 
be  placed  in  large  mass. 


FIRE  RESISTANCE. 

In  addition  to  its  permanence  and  strength,  concrete  is  especially  suited  to 
the  construction  of  warehouses,  terminal  buildings,  bridges,  stations,  coal 
pockets  and  similar  structures  on  account  of  its  undoubtable  fire-resisting 
qualities.  Actual  fires  and  fire  tests  have  demonstrated  time  and  again  the 
ability  of  reinforced  concrete  to  withstand  even  extraordinary  fires.  This  is 
a  valuable  asset  not  only  for  buildings  and  warehouses,  but  particularly  for 
structures  to  be  used  for  the  storage  of  coal,  since  the  railroads  of  this  country 

12 


have  suffered  in  the  past  much  inconvenience  and  expense  through  the  use  of 
inferior  bins  of  timber  or  steel.  The  spontaneous  combustion  to  which  coal  is 
subject  when  stored  in  great  quantities  not  only  results  in  the  loss  of  the  coal 
itself  and  the  damaging  of  much  valuable  machinery,  but  also  in  the  destruc- 
tion of  the  bin  if  it  is  constructed  either  of  wood  or  steel. 

As  a  result  of  the  lessons  taught  by  the  recent  terrible  fires  along  the 
waterfront  of  Hoboken,  the  new  piers  designed  to  replace  those  burned  down 
in  the  fire  of  1904  are  to  be  built  entirely  of  concrete  and  steel  construction. 

VERSATILITY  OF  DESIGN. 

Concrete  enjoys  a  wider  range  of  possible  use  and  varieties  of  design  than 
any  known  building  material.  An  evidence  of  its  adaptability  to  the  endless 
variety  of  uses  in  railway  design  is  shown  by  the  thirty-five  classes  of  con- 
struction described  in  the  text  of  this  book. 

WATER-TIGHTNESS. 

It  was  formerly  thought  necessary  to  waterproof  a  structure  where  it  came 
in  contact  with  ground  water.  But  now  by  using  a  proper  amount  of  rein- 
forcement to  prevent  cracks  due  to  shrinkage  from  temperature  and  by  properly 
forming  the  joints,  concrete  is  used  in  many  cases  with  no  surface  waterproof- 
ing. In  the  Philadelphia -sub way  after  experimenting  with  various  methods 
of  waterproofing  it  was  decided  to  depend  entirely  on  the  concrete  itself,  and 
in  the  New  York  subway  no  waterproofing  is  now  being  used  above  high- 
water  level.  Concrete  is  especially  adapted  for  use  in  the  construction  of  con- 
duits, dams,  tanks,  reservoirs  and  other  structures  which,  to  accomplish  their 
purpose,  must  be  essentially  water-tight. 

ALTERATIONS. 

Owing  to  the  difficulty  in  tearing  it  down  concrete  is  not  suitable  for  a 
temporary  structure.  While  radical  changes  in  construction  are  not  readily 
made,  holes  may  be  cut  in  walls  and  floors,  at  greater  expense  than  in  wood, 
but  without  serious  difficulty. 

STRENGTHENING  OLD  MASONRY. 

Concrete  from  its  very  nature  is  well  adapted  for  reinforcing  or  strength- 
ening and  protecting  old  stone  masonry  which  is  being  disintegrated  by  the 
action  of  the  weather. 

13 


FOUNDATIONS. 

Concrete  has  been  used  for  foundations  in  railroad  construction  for  years; 
in  fact,  until  recently  this  was  practically  the  only  use.  With  the  development 
of  design,  reinforcement  has  been  introduced  which  often  saves  much  material. 


T 

> 


i 


FIG.  1.— RETAINING  WALL  AND  PROTECTION  PIER,  BRONX  IMP.,  N.  Y.  C.  &  H.  R.  R.R. 


CHAPTER  II. 


DESIGN  AND  CONSTRUCTION. 

Although  the  use  of  reinforced  concrete  is  comparatively  recent,  there  have 
been  sufficient  tests  and  the  theory  is  far  enough  developed  to  design  with 
absolute  security  not  only  masonry  structures  like  foundations,  bridges,  re- 
taining walls,  abutments  and  piers,  but  structures  embodying  beams  and  slabs, 
such  as  girders,  bridges,  coaling  stations  and  power  plants. 

Numerous  tests  have  been  made  during  the  last  few  years  on  almost  all  the 
details  of  concrete  construction  not  only  at  nearly  all  the  universities,  but  the 
Structural  Materials  Testing  Laboratories  at  St.  Louis  under  the  direction  of 
the  United  States  Geological  Survey  has  been  taking  up  the  subject  in  a  scien- 
tific manner. 

Besides  this  experimental  work,  the  use  of  reinforced  concrete  is  so  wide- 
spread that  practice  is  rapidly  confirming  the  theoretical  demonstrations. 

CEMENT. 

While  brief  specifications  for  cement  may  be  sufficiently  comprehensive  for 
work  of  minor  importance,  the  standard  specifications  adopted  by  the  Ameri- 
can Society  for  Testing  Materials*  are  generally  adopted  for  important  work 
throughout  the  country. 

SAND. 

The  selection  of  sand  for  use  in  concrete  work  is  quite  as  important  as  that 
of  the  cement  and  it  should  be  carefully  tested  for  all  important  structures. 
As  a  guide  for  the  proper  selection  of  the  aggregates  the  following  is  quoted 
from  the  Progress  Report  of  the  Joint  Committee  on  Concrete  and  Reinforced 
Concrete,  igog.f 

"a.  FINE  AGGREGATE  consists  of  sand,  crushed  stone,  or  gravel 
screenings,  passing  when  dry  a  screen  having  %-inch  diameter  holes.  It 
should  be  preferably  of  silicious  material,  clean,  coarse,  free  from  vege- 
table loam  or  other  deleterious  matter. 


*These  may  be  obtained  by  addressing  The  Atlas  Portland  Cement  Company. 

tAffiliated  Committees  of  American  Society  of  Civil  Engineers,  American  Society 
for  Testing  Materials,  American  Railway  Engineering  and  Maintenance  of  Way  Asso- 
ciation, Association  of  American  Portland  Cement  Manufacturers. 

15 


"A  gradation  of  the  grain  from  fine  to  coarse  is  generally  advan- 
tageous. 

"Mortars  composed  of  one  part  Portland  cement  and  three  parts  fine 
aggregate  by  weight  when  made  into  briquets  should  show  a  tensile 
strength  of  at  least  70  per  cent  of  the  strength  of  1 13  mortar  of  the  same 
consistency  made  with  the  same  cement  and  standard  Ottawa  sand." 

BROKEN  STONE  AND  GRAVEL. 

"b.  COARSE  AGGREGATE  consists  of  inert  material,  such  as 
crushed  stone,  or  gravel,  which  is  retained  on  a  screen  having  %-inch 
diameter  holes.  The  particles  should  be  clean,  hard,  durable,  and  free 
from  all  deleterious  material.  Aggregates  containing  soft,  flat  or  elon- 
gated particles  should  be  excluded  from  important  structures.  A  grada- 
tion of  size  of  the  particles  is  generally  advantageous. 

"The  maximum  size  of  the  coarse  aggregate  shall  be  such  that  it  will 
not  separate  from  the  mortar  in  laying  and  will  not  prevent  the  concrete 
from  fully  surrounding  the  reinforcement  or  filling  all  parts  of  the  forms. 
Where  concrete  is  used  in  mass,  the  size  of  the  coarse  aggregate  may  be 
such  as  to  pass  a  3-inch  ring.  For  reinforced  members  a  size  to  pass  a 
i-inch  ring,  or  a  smaller  size,  may  be  used. 

"Cinder  concrete  is  not  suitable  for  reinforced  concrete  structures,  and 
may  be  safely  used  only  in  mass  for  very  light  loads  or  for  fireproofing. 

"Where  cinder  concrete  is  permissible  the  cinders  used  as  the  coarse 
aggregate  should  be  composed  of  hard,  clean,  vitreous  clinker,  free  from 
sulphides,  unburned  coal,  or  ashes." 

Owing  to  the  presence  of  vegetable  loam  or  other  deleterious  matter,  it  is 
often  necessary  to  wash  the  aggregates,  and  the  drawing  in  Fig.  2  shows  an 
apparatus  designed  by  Mr.  Allen  Hazen  and  Mr.  William  H.  Ham  and  used 
with  good  success  by  the  contractors,  Messrs.  Tucker  and  Vinton. 

STEEL. 

There  is  frequently  a  question  as  to  the  use  of  high  or  low  carbon  steel. 
High  carbon  steel  is  very  apt  to  be  brittle  unless  it  is  made  so  as  to  pass  severe 
tests,*  when  it  can  be  depended  upon. 

It  is  generally  economical  to  use  ordinary  medium  steel  unless  perhaps  for 
temperature  reinforcement,  when  steel  with  high  elastic  limit  and  deformed 
section  is  especially  good. 


*See  Specifications  in  Taylor  &  Thompson's  "Concrete  Plain  and  Reinforced,"  Sec- 
ond Edition,  1909.    John  Wiley  &  Sons,  New  York,  publishers. 

16 


For  ordinary  uses,  deformed  bars,  that  is,  bars  with  irregular  sections, 
while  satisfactory  and  in  some  cases  better  than  ordinary  round  bars,  are 
usually  not  absolutely  necessary. 


PROPORTIONS. 

In  such  a  broad  field  of  construction  as  is  found  in  railroad  work,  it  is  im- 
possible to  give  any  general  recommendations  as  to  the  proper  proportions  to 
use,  as  this  depends  so  much  on  the  structure  itself.  For  any  specific  struc- 
ture, the  reader  is  referred  to  the  proportions  adopted  in  the  construction  of 
similar  structures  described  in  the  text. 

The  standard  method  for  measuring  parts  is  to  assume  one  part  as  equal  to 
4  bags  of  cement,  or  one  barrel.  In  measuring  the  sand  and  stone  a  barrel  is 
assumed  as  3.8  cubic  feet.  The  actual  volume  of  a  cement  barrel  averages 
about  3.5  cubic  feet,  but  the  3.8  cubic  feet  has  been  adopted  generally  in  prac- 
tice as  corresponding  to  a  weight  of  100  pounds  of  cement  to  the  cubic  foot, 
which  is  that  of  the  cement  partially  compacted ;  thus  proportions  1 12 14 
means  one  barrel  (or  4  bags)  Portland  cement,  7.6  cubic  feet  sand  measured 
loose  and  15.2  cubic  feet  of  broken  stone  or  gravel  measured  loose. 


MIXING.* 

"The  ingredients  of  concrete  should  be  thoroughly  mixed  to  the  desired 
consistency,  and  the  mixing  should  continue  until  the  cement  is  uniformly  dis- 
tributed and  the  mass  is  uniform  in  color  and  homogeneous,  since  maximum 
density  and  therefore  greatest  strength  of  a  given  mixture  depends  largely  on 
thorough  and  complete  mixing. 

"(a)  Measuring  Ingredients.  Methods  of  measurements  of  the  pro- 
portions of  the  various  ingredients,  including  the  water,  should  be  used, 
which  will  secure  separate  uniform  measurements  at  all  times. 

"(b)  Machine  Mixing.  When  the  conditions  will  permit,  a  machine 
mixer  of  a  type  which  insures  the  uniform  proportioning  of  the  materials 
throughout  the  mass  should  be  used,  since  a  more  thorough  and  uniform 
consistency  can  be  thus  obtained. 

"(c)  Hand  Mixing.  When  it  is  necessary  to  mix  by  hand,  the  mix- 
ing should  be  on  a  water-tight  platform  and  especial  precautions  should 
be  taken  to  turn  the  materials  until  they  are  homogeneous  in  appearance 
and  color." 

*From  Joint  Committee's  recommendations,  see  footnote,  page  15. 

18 


CONSISTENCY. 

The  required  consistency  varies  with  the  class  of  work.  Concrete  is 
strongest  when  not  too  wet,  but  of  a  medium  jelly-like  consistency.  For  rein- 
forced concrete  it  must  be  softer,  so  that  it  can  just  flow  sluggishly  around 
the  steel  and  into  the  forms.  At  the  same  time  it  should  be  stiff  enough  to  be 
conveyed  from  the  mixer  to  the  forms  without  separation  of  the  coarse  aggre- 
gate from  the  mortar. 

PLACING.* 

"(a)  Methods.  Concrete  after  the  addition  of  water  to  the  mix  should 
be  handled  rapidly,  and  in  as  small  masses  as  practicable  from  the  place  of 
mixing  to  the  place  of  final  deposit,  and  under  no  circumstances  should  con- 
crete be  used  that  has  partially  set  before  final  placing.  A  slow  setting  cement 
should  be  used  when  a  long  time  is  liable  to  occur  between  mixing  and  final 
placing. 

"The  concrete  should  be  deposited  in  such  a  manner  as  will  permit  the 
most  thorough  compacting,  such  as  can  be  obtained  by  working  with  a 
straight  shovel  or  slicing  tool  kept  moving  up  and  down  until  all  the  ingredi- 
ents have  settled  in  their  proper  place  by  gravity  and  the  surplus  water  forced 
to  the  surface. 

"In  depositing  the  concrete  under  water,  special  care  should  be  exercised 
to  prevent  the  cement  from  being  floated  away,  and  to  prevent  the  formation 
of  laitance  which  hardens  very  slowly  and  forms  a  poor  surface  on  which  to 
deposit  fresh  concrete.  Laitance  is  formed  in  both  still  and  running  water, 
and  should  be  removed  before  placing  fresh  concrete. 

"Before  placing  the  concrete  care  should  be  taken  to  see  that  the  forms  are 
substantial  and  thoroughly  wetted  and  the  space  to  be  occupied  by  the  con- 
crete free  from  debris.  When  the  placing  of  the  concrete  is  suspended,  all 
necessary  grooves  for  joining  future  work  should  be  made  before  the  concrete 
has  had  time  to  set. 

"When  work  is  resumed,  concrete  previously  placed  should  be  roughened, 
thoroughly  cleansed  of  foreign  material  and  laitance,  drenched  and  slushed 
with  a  mortar  consisting  of  one  part  Portland  cement  and  not  more  than  two 
parts  fine  aggregate. 

"The  faces  of  concrete  exposed  to  premature  drying  should  be  kept  wet  for 
a  period  of  at  least  seven  days. 

"(b)  Freezing  Weather.  The  concrete  for  reinforced  structures  should 
not  be  mixed  or  deposited  at  a  freezing  temperature,  unless  special  precau- 


*From  Joint  Committee's  recommendations,  see  footnote,  page   15. 

19 


tions  are  taken  to  avoid  the  use  of  materials  containing  frost  or  covered  with 
ice  crystals,  and  in  providing  means  to  prevent  the  concrete  from  freezing 
after  being  placed  in  position  and  until  it  has  thoroughly  hardened. 

"(c)  Rubble  Concrete.  Where  the  concrete  is  to  be  deposited  in  massive 
work  its  value  may  be  improved  and  its  cost  materially  reduced  through  the 
use  of  clean  stones  thoroughly  embedded  in  the  concrete  as  near  together  as  is 
possible  and  still  entirely  surrounded  by  the  concrete." 

JOINTS. 

In  walls  of  any  considerable  length  it  is  necessary  to  provide  against 
shrinkage  and  temperature  cracks.  The  general  practice  for  walls  of  plain 
concrete  is  to  place  contraction  joints  at  intervals  of  from  30  to  50  feet,  but 
in  many  instances  this  has  not  been  sufficient  and  the  author  recommends  a 
spacing  of  from  20  to  30  feet.  Walls  can  be  built  with  no  joints  by  providing 
sufficient  reinforcement  to  so  distribute  the  temperature  stresses  that  the 
cracks  will  be  very  minute  and  scarcely  noticeable  on  close  inspection. 

SURFACES. 

The  proper  treatment  to  give  a  pleasing  appearance  to  exposed  surfaces  is 
one  of  the  most  difficult  problems  in  concrete  construction  and  a  number  of 
different  methods  have  been  employed,  all  of  which  are  illustrated  by  different 
structures  described  in  the  text. 

FORMS.* 

"Forms  should  be  substantial  and  unyielding,  so  that  the  concrete  shall 
conform  to  the  designed  dimensions  and  contours,  and  should  be  tight  to  pre- 
vent the  leakage  of  mortar. 

"The  time  for  the  removal  of  forms  is  one  of  the  most  important  steps  in 
the  erection  of  a  structure  of  concrete  or  reinforced  concrete.  Care  should  be 
taken  to  inspect  the  concrete  and  ascertain  its  hardness  before  removing  the 
forms. 

"So  many  conditions  affect  the  hardening  of  concrete  that  the  proper  time 
for  the  removal  of  the  forms  should  be  decided  by  some  competent  and  re- 
sponsible person,  especially  where  the  atmospheric  conditions  are  unfavor- 
able." 

WATERPROOFING. 

While  many  expedients  have  been  used  to  render  concrete  impervious  to 
water,  experience  has  shown  that,  where  the  concrete  is  proportioned  to  realize 

*Sce  footnote,  page  15. 

20 


the  greatest  practicable  density  and  is  mixed  to  a  rather  wet  consistency,  it  is 
sufficiently  impervious  itself,  for  ordinary  purposes,  without  further  treatment. 
The  proportions  generally  used  to  resist  the  percolation  of  water  range  from 
i  :i  :2  to  1 12  14,  the  latter  being  the  most  common  mixture.  Sometimes,  where 
the  mass  of  the  concrete  is  considerable,  or  where  the  walls  are  thin,  a  material 
like  hydrated  lime  or  dry  powdered  clay  may  be  efficient  for  void  filling  and 
permit  the  use  of  leaner  proportions.  In  subways,  long  retaining  walls,  and 
reservoirs,  cracks  can  be  prevented  by  horizontal  reinforcement  properly  pro- 
portioned and  located.  In  any  case,  for  water-tight  work  the  concrete  should 
be  mixed  wet  enough  to  entirely  surround  the  reinforcing  metal  and  flow 
against  the  forms. 

Asphaltic  or  coal  tar  preparations  applied  either  as  a  mastic  or  with  paper 
or  felt  are  used  to  good  advantage  where  it  is  deemed  unadvisable  to  rely 
upon  the  natural  imperviousness  of  the  concrete  itself. 

DESIGN  OF  PLAIN  CONCRETE. 

In  the  design  of  plain  concrete,  sections  should  be  so  proportioned  as 
to  avoid  tensile  stresses,  and  while  this  may  be  accomplished  in  the  case  of 
rectangular  shapes  by  keeping  the  line  of  pressure  within  the  middle  third  of 
the  section,  in  very  large  structures  a  more  exact  analysis  may  be  required. 

Inasmuch  as  structures  of  massive  concrete  are  able  to  resist  any  unbal- 
anced later  forces  by  reason  of  their  weight,  a  relatively  cheap  and  weak 
concrete  is  often  suitable  for  such  conditions. 

BENDING  MOMENTS. 

In  reinforced  concrete  design  as  much  variation  may  be  had  in  the  results 
by  the  selection  of  the  bending  moments  as  in  the  choosing  of  working 
stresses.  If  the  members  are  continuous  beams  or  slabs,  special  care  must 
be  taken  in  the  design  at  the  supports,  since  there  is  much  and  frequently 
more  stress  there  than  at  the  middle  of  the  span.  It  is  not  safe  practice  to 
design  a  continuous  beam  in  the  center  as  though  it  was  simply  supported  and 
then  pay  no  attention  to  the  design  over  the  supports. 

Good  practice  and  the  recommendations  also  of  the  Joint  Committee  on 
Concrete  and  Reinforced  Concrete  (1909)  sanction  the  following  formulas 
for  bending  moments : 

Let  P  =  concentrated  load  in  pounds 

w  =  unit  distributed  load  in  pounds  per  square  foot 

(including  the  dead  load) 

1  =  length  of  member  between  centers  of  support  in  feet 
M  =  bending  moment  in  foot  pounds. 

21 


To  transform  the  bending  moment  to  inch  pounds,  multiply  by  12. 
For  beams  and  slabs  simply  supported  at  the  ends  and  not  continuous : 

M  =  1/8  wl2  for  distributed  load  (i) 

and 

M  =  1/8  wl2  +  %  PI  for  distributed  load  plus  a  load  concentrated 

at  the  center  (2) 

For  beams  and  slabs  truly  continuous  and  thoroughly  reinforced  over 
the  supports: 

M  =  i/i 2  wl2  at  the  center  of  the  member  (3) 

and  —  M  =  1/12  wP  at  the  ends  of  the  member  (4) 

For  beams  and  slabs  partially  continuous,  as  end  spans,  or  for  continu- 
ous members  of  2  or  3  spans : 

M  =  i/io  wl2  at  the  center  of  the  member  (5) 

The  negative  bending  moments  which  exist  at  the  supports  must  be  pro- 
vided for  by  steel  rods  carried  over  the  top  of  the  support  for  tension  and  by  a 
sufficient  amount  of  concrete  at  the  bottom  of  the  beam  near  the  support  to 
take  the  compression. 

If  a  part  of  the  tension  rods  are  bent  up  on  an  incline  from  about  one-quar- 
ter points  in  the  beam  so  as  to  pass  horizontally  through  the  top  of  the  beam 
at  the  supports  they  must  extend  over  the  supports  for  a  sufficient  distance 
to  transmit  the  compressive  stress  there,  or  must  be  firmly  connected  with  cor- 
responding rods  in  the  adjacent  bay.  The  total  steel  in  the  top  must  be  suffi- 
cient to  resist  the  tension  due  to  negative  moment,  and  the  concrete  and  steel 
in  the  bottom  next  to  the  support,  sufficient  to  resist  the  compression. 

For  cantilever  beams,  that  is,  beams  with  one  end  fixed  and  the  other  end 
free,  where  the  maximum  bending  moment  is  at  the  point  of  support  and  the 
tension  is  in  the  top  of  the  beam,  the  following  formulas  hold: 

With  a  uniformly  distributed  load  over  the  length  of  the  beam: 

_  M  =  y2  wP  at  the  support 
If  also  a  live  load  is  concentrated  at  the  end 

—  M  =  PI  +  y2  wP 

DESIGN  OF  REINFORCED  CONCRETE. 

In  designing  a  reinforced  concrete  member  it  is  not  sufficient  to  simply  de- 
termine the  amount  of  steel  required  to  resist  the  tensile  stresses,  but  a  most 
careful  analysis  must  be  made  of  all  parts  of  the  structure. 

22 


The  correct  design  of  reinforced  concrete  beams  and  girders  involves  the 
following  studies : 

(1)  The  bending  moments  due  to  the  live  and  dead  loads. 

(2)  Dimensions  of  beams  which  will  prevent  an  excessive  compression  of 
the  concrete  in  the  top  and  which  will  give  the  depth  and  width  which  is  other- 
wise most  economical. 

(3)  Number  and  size  of  rods  to  sustain  tension  in  the  bottom  of  the  beam. 

(4)  Shear  or  diagonal  tension  in  the  concrete. 

(5)  Value  of  bent-up  rods  to  resist  shear  or  diagonal  tension. 

(6)  Stirrups  to  supplement  the  bent-up  rods  in  assisting  to  resist  the 
shear  or  diagonal  tension. 

(7)  Steel  over  the  supports  to  take  the  tension  due  to  negative  bending 
moment. 

(8)  Concrete  in  compression  at  the  bottom  of  the  beam  near  the  supports 
due  to  negative  bending  moment. 

(9)  Length  of  rods  to  prevent  slipping. 
(10)     End  connections  at  wall. 

WORKING  STRESSES. 

The  working  stresses  for  static  loads  given  below  follow  the  recommenda- 
tions of  the  Progress  Report  of  the  Joint  Committee  on  Concrete  and  Rein- 
forced Concrete,  1909.* 

"General  Assumptions.  The  following  working  stresses  are  recom- 
mended for  static  loads.  Proper  allowances  for  vibration  and  impact  are 
to  be  added  to  live  loads  where  necessary  to  produce  an  equivalent  static 
load  before  applying  the  unit  stresses  in  proportioning  parts. 

"In  selecting  the  permissible  working  stress  to  be  allowed  on  concrete, 
we  should  be  guided  by  the  working  stresses  usually  allowed  for  other 
materials  of  construction,  so  that  all  structures  of  the  same  class,  but 
composed  of  different  materials,  may  have  approximately  the  same  degree 
of  safety. 

"The  stresses  for  concrete  are  proposed  for  concrete  composed  of  one 
part  Portland  cement  and  six  parts  aggregate,  capable  of  developing  an 
average  compressive  strength  of  2,000  pounds  per  square  inch  at  twenty- 
eight  days,  when  tested  in  cylinders  8  inches  in  diameter  and  16  inches 
long,  under  laboratory  conditions  of  manufacture  and  storage,  using  the 
same  consistency  as  is  used  in  the  field.  In  considering  the  factors  rec- 


*The  form  of  the  tabulation  is  as  given  in  the  Report  of  the  Committee  on  Rein- 
forced Concrete  of  the  National  Association  of  Cement  Users,  1909,  Sanford  E. 
Thompson,  Chairman. 

23 


ommended  with  relation  to  this  strength,  it  is  to  be  borne  in  mind  that  the 
strength  at  twenty-eight  days  is  by  no  means  the  ultimate  which  will  be 
developed  at  a  longer  period,  and  therefore  they  do  not  correspond  with 
the  real  factor  of  safety.  On  concretes  in  which  the  material  of  the 
aggregate  is  inferior,  all  stresses  should  be  proportionally  reduced,  and 
similar  reduction  should  be  made  when  leaner  mixes  are  to  be  employed. 
On  the  other  hand,  if,  with  the  best  quality  of  aggregates,  the  richness  is 
increased,  an  increase  may  be  made  in  all  working  stresses  proportional  to 
the  increase  in  compressive  strength  at  28  days,  but  this  increase  shall  not 
exceed  25  per  cent. 

"Diagonal  Tension.  In  beams  where  diagonal  tension  is  taken  by 
concrete,  the  vertical  shearing  stresses  should  not  exceed 

2  per  cent  of  compressive  strength  at  twenty-eight  days,   or  40 
pounds  per  square  inch  for  2,000  pound  concrete. 

"Bond  for  Plain  Bars.  Bonding  stress  between  concrete  and  plain 
reinforcing  bars, 

4  per  cent  of  compressive  strength  at  twenty-eight  days,  or  80. 
pounds  per  square  inch  for  2,000  pound  concrete. 

For  drawn  wire, 

2  per  cent,  or  40  pounds  on  2,000  pound  concrete. 

"Bond  for  Deformed  Bars.*  Bonding  stress  between  concrete  and 
deformed  bars  may  be  assumed  to  vary  with  the  character  of  the  bar  from 

5  per  cent  to  lYz  per  cent  of  the  compressive  strength  of  the  con- 
crete at  twenty-eight  days  or  from 

100  to  154  pounds  per  square  inch  for  2,000  pound  concrete. 
"Reinforcement.     The  tensile  stress  in  steel  should  not  exceed  16,000 
pounds   per   square   inch.     The   compressive   stress   in   reinforcing   steel 
should  not  exceed  16,000  pounds  per  square  inch,  or  fifteen  times  the 
working  compressive  stress  in  the  concrete. 

"Modulus  of  Elasticity.  It  is  recommended  that  in  all  computations 
the  modulus  be  assumed  as  1/15  that  of  steel;  that  is,  that  a  ratio  of  fif- 
teen be  employed. 

"Bearing.f  For  compression  on  surface  of  concrete  larger  than  loaded 
area, 

32.5  per  cent  of  compressive  strength  at  twenty-eight  days  or  650 
pounds  per  square  inch  on  2,000  pound  concrete. 

"Plain  Columns.  Plain  columns  or  piers  whose  length  does  not  ex- 
ceed twelve  diameters, 

*No  recommendation  for  deformed  bars  is  given  in  the  report  of  the  Joint  Commit- 
tee. 

tFor  beams  and  girders  built  into  pockets  in  concrete  walls  the  lower  compressive 
stress  of  450  pounds  per  square  inch  should  not  be  exceeded. 

24 


22*4  per  cent  of  compressive  strength  at  twenty-eight  days,  or  450 
pounds  per  square  inch  on  2,000  pound  concrete. 

"Reinforced  Columns,  (a)  Columns  with  longitudinal  reinforcement 
only,  the  unit  stress  recommended  for  plain  columns. 

(b)  Columns  with  reinforcement  of  bands  or  hoops,  as  specified  be- 
low, stresses  20  per  cent  higher  than  given  for  (a). 

(c)  Columns  reinforced  with  not  less  than  i  per  cent  and  not  more 
than  4  per  cent  of  longitudinal  bars  and  with  bands  or  hoops,  stresses  45 
per  cent  higher  than  given  for  (a). 

(d)  Columns   reinforced   with   structural  steel   column   units   which 
thoroughly  encase  the  concrete  core,   stresses  45   per  cent  higher  than 
given  for  (a)." 

"In  all  cases,  in  addition  to  the  stress  borne  by  the  concrete  given  above, 
longitudinal  reinforcement  is  assumed  to  carry  its  proportion  of  stress  in  ac- 
cordance with  the  ratio  of  its  elasticity  to  concrete.  For  example,  with  a 
working  stress  in  concrete  of  450  pounds  per  square  inch,  the  longitudinal  re- 
inforcement may  be  assumed  to  carry  15  X  450  =  6,750  pounds  per  square 
inch. 

"The  hoops  or  bands  are  not  to  be  counted  upon  directly  as  adding  to  the 
strength  of  the  column. 

"Bars  composing  longitudinal  reinforcement  shall  be  straight  and  shall  have 
sufficient  lateral  support  to  be  securely  held  in  place  until  the  concrete  is  set. 
"Where  bands  or  hoops  are  used,  the  total  amount  of  such  reinforcement 
shall  be  not  less  than  i  per  cent  of  the  volume  of  the  column  enclosed.  The 
clear  spacing  of  such  bands  or  hoops  shall  be  not  greater  than  one-fourth  the 
diameter  of  the  enclosed  column.  Adequate  means  must  be  provided  to  hold 
bands  or  hoops  in  place  so  as  to  form  a  column,  the  core  of  which  shall  be 
straight  and  well  centered. 

"Bending  stresses  due  to  eccentric  loads  must  be  provided  for  by  increasing 
the  section  until  the  maximum  stress  does  not  exceed  the  values  above  speci- 
fied. 

"Compression  in  Extreme  Fiber.  For  extreme  fiber  stress  of  beams 
calculated  for  constant  modulus  of  elasticity. 

32.5  per  cent  of  the  compressive  strength  at  twenty-eight  days,  or 
650  pounds  per  square  inch  for  2,000  pound  concrete. 
"Adjacent  to  the  support  of  continuous  beams,  stresses  15  per  cent 
greater  may  be  allowed. 

"Shear.  Pure  shearing  stresses  uncombined  with  compression  or  ten- 
sion. 6  per  cent  of  compressive  strength  at  twenty-eight  days,  or  120 
pounds  per  square  inch  for  2,000  pound  concrete." 


CHAPTER  III. 


BRIDGES. 

One  of  the  most  important  applications  of  concrete  to  railroad  construction 
is  in  the  building  of  bridges.  By  the  intelligent  use  of  reinforced  concrete, 
bridges  are  being  designed  which  are  superior  to  similar  steel,  masonry  or 
wooden  structures  from  an  artistic,  structural  and  economic  standpoint. 

While  the  life  of  a  wooden  bridge  is  about  9  years  and  of  a  steel  bridge 
probably  not  over  30  to  40  years,  and  even  then  with  a  continual  outlay  for 
repairs  and  painting  in  addition  to  careful  inspection,  a  concrete  bridge  will 
last  almost  indefinitely  and  with  practically  no  maintenance.  In  addition  to 
its  natural  permanence,  such  a  bridge  is  proof  against  tornadoes,  high  water 
and  fire. 

Steel  and  wooden  bridges  grow  weaker  from  rust  and  decay  and  in  a  few 
years  the  day  comes  when  the  bridge  of  decreasing  strength  is  overloaded  by 
the  increasing  weight  of  rolling  stock  and  requires  either  strengthening  or  re- 
placing. Concrete  bridges  on  the  other  hand  grow  stronger  with  age  and  in 
probably  as  rapidly  an  increasing  ratio  as  the  increase  of  traffic. 

A  concrete  bridge  is  free  from  the  excessive  vibrations  often  experienced 
in  steel  bridges  and  from  disagreeable  noise. 

Track  is  easily  maintained  on  such  a  structure,  since  the  ordinary  track 
ties  and  ballast  take  the  place  of  the  more  expensive  bridge  ties  of  a  steel 
structure. 

In  the  construction  of  a  concrete  bridge  there  is  no  obstruction  of  traffic 
from  swinging  booms  as  is  the  case  when  setting  stone  of  large  dimensions  in 
masonry  bridges,  nor  so  much  difficulty  in  securing  the  necessary  skilled  labor 
during  times  when  the  building  trades  are  active.  The  materials  used  can 
generally  be  obtained  in  the  immediate  vicinity  of  the  bridge  site. 

The  cost  of  a  reinforced  concrete  bridge  in  almost  all  cases  will  be  consid- 
erably less  than  that  of  a  stone  masonry  structure  and  will  not  greatly,  if  at 
all,  exceed  that  of  a  steel  bridge,  when  the  cost  of  piers  and  abutments  is  in- 
cluded in  the  comparison.  Even  when  the  cost  of  the  steel  is  less,  the  differ- 
ence is  more  than  counteracted  by  the  practically  negligible  maintenance  costs 
of  the  concrete  structure. 


27 


ARCH  BRIDGES.* 

While  arch  bridges  may  be  constructed  of  either  plain  or  reinforced  con- 
crete, the  latter  type  is  usually  the  most  satisfactory,  as  the  steel  reinforce- 
ment not  only  permits  the  use  of  less  material,  but  it  also  adds  to  the  safety 
against  settlements  of  foundations  or  centerings,  and  temperature  stresses, 
The  Wallkill  River  bridge  shown  in  Fig.  3  is  an  interesting  example  of  plain 
concrete  construction,  while  the  Jackson  Street  arch,  the  Paulins  Kill  viaduct 
and  the  Vermillion  River  Bridge,  shown  in  Figs.  4,  8  and  9,  are  types  of  rein- 
forced arch  bridges. 

Arches  are  classified  in  various  ways,  but  the  most  simple  classification  is 
in  reference  to  the  method  of  the  construction  of  the  spandrels,  or  spaces 
above  the  upper  surface  of  the  arch  ring  and  below  the  road-bed  level.  These 
spaces  are  either  filled  in  solid  with  loose  filling  or  are  left  open  by  skeleton 
spandrel  construction  consisting  of  slabs  and  beams  supported  on  columns  or 
cross-walls  resting  on  the  arch  ring. 

SOLID  FILLED  SPANDRELS.  This  type  of  construction  is  generally 
employed  for  arches  of  spans  under  100  feet.  While  the  solid-filled  spandrels 
usually  consist  of  an  embankment  of  earth,  sand  or  cinders  enclosed  between 
solid  spandrel  walls  having  the  common  trapezoidal  retaining-wall  section,  or 
between  reinforced  spandrel  walls,  sometimes  a  filling  of  very  lean  concrete  is 
used  in  place  of  the  loose  material,  when  the  spandrel  walls  become  an  integ- 
ral part  of  the  filling.  The  loose  filling  between  spandrel  walls  is  deposited  in 
thin  layers  and  thoroughly  tamped  by  ramming,  rolling  or  flooding  it  in  with 
water. 

The  Jackson  Street  arch,  described  on  page  30,  is  an  example  of  the  solid 
fill  spandrel  type  of  construction. 

SKELETON  SPANDREL  CONSTRUCTION.  For  spans  of  about  100 
feet  or  over  the  skeleton  spandrel  construction  is,  on  account  of  its  reduced 
weight  and  cost,  found  most  advantageous. 

In  addition  to  the  advantage  resulting  from  a  reduction  of  the  load  on  the 
main  arch  ring  and  foundations  this  type  of  construction  when  well  handled 
furnishes  an  opportunity  to  introduce  architectural  effects  of  great  beauty. 
By  doing  away  with  the  long  and  heavy  solid  spandrel  walls  the  trouble  with 
temperature  strains  is  greatly  lessened  in  this  type  of  construction. 

The  Paulins  Kill  Viaduct  and  the  Vermillion  River  Bridge,  described  on 
pages  34  and  36,  are  examples  of  skeleton  spandrel  construction. 

Another  form  of  skeleton  spandrel  construction,  an  example  of  which  is 
found  in  the  Connecticut  Avenue  Bridge,  Washington,  D.  C.,  consists  of  hol- 

*For  theory  and  methods  of  design  see  Taylor  &  Thompson's  "Concrete  Plain  and 
Reinforced,"  Second  Edition,  1909,  or  Howe's  "Symmetrical  Masonry  Arches."  John 
Wiley  &  Sons,  New  York,  publishers. 

28 


low  spandrels  with  curtain  walls  forming  a  cellular  spandrel  construction  in 
which  the  roadway  is  carried  on  a  system  of  braced  columns  and  beams  en- 
closed by  thin  curtain  walls  on  each  side  of  the  bridge. 

EXPANSION  JOINTS.  To  provide  for  the  action  of  temperature 
strains,  expansion  joints  are  generally  constructed  in  the  spandrels  where  they 
meet  the  abutments  and  usually  also  at  one  or  more  points  between  the  abut- 
ments and  crown  of  the  arch.  Some  engineers  place  a  vertical  expansion  joint 
over  each  springing  line  and  at  a  point  about  10  feet  each  side  of  the  crown. 
These  joints  which  cut  the  spandrels  vertically  from  the  coping  of  the  parapet 
wall  to  the  arch  ring  are  either  constructed  as  mere  planes  of  weakness  in  the 
concrete  or  as  actual  joints  filled  with  one  or  more  layers  of  felt,  corrugated 
paper  or  some  other  partially  elastic  material. 

Another  method  which  is  sometimes  adopted  is  to  entirely  omit  the  ex- 
pansion joints  and  resist  the  temperature  strains  by  providing  sufficient  rein- 
forcing metal  throughout  the  structure. 

WATERPROOFING.  The  top  of  the  arch  and  the  lower  parts  of  the 
spandrel  walls  are  usually  waterproofed  in  order  to  facilitate  drainage  and 
keep  accumulated  water  from  penetrating  the  arch  ring. 

In  addition  to  the  structures  described  below,  a  number  of  other  arch 
bridges  are  shown  among  the  miscellaneous  photographs  in  the  back  of  the 
book. 

JACKSON  STREET  ARCH,  C.  R.  R.  OF  N.  J.  As  will  be  seen  by  the 
drawings  in  Fig.  5,  page  32,  which  show  the  essential  features  of  design  and 
construction,  this  bridge  consists  of  a  reinforced  concrete  arch  of  54  ft.  3  inch 
clear  span  with  axis  on  a  skew  of  22°  2'  with  the  axis  of  the  street.  The  pho- 
tograph in  Fig.  4  shows  the  finished  arch. 

The  abutments  and  wing  walls  rest  on  lo-inch  piles,  the  last  three  rows  in 
each  abutment  being  driven  with  a  batter  to  correspond  with  the  inclination 
of  the  line  of  pressure.  These  piles  were  cut  off  below  water  level,  which  is 
about  10.87  feet  below  the  surface  of  the  street,  and  a  bed  of  broken  stone  3 
feet  thick  was  rammed  around  them  to  within  6  inches  of  the  tops  where  the 
concrete  work  started. 

With  the  exception  of  an  open  expansion  joint,  like  a  vertical  tongue  and 
groove,  between  the  ends  of  the  abutments  and  the  ends  of  the  wing  walls  the 
bridge  was  constructed  as  a  monolith.  For  the  arch  ring  the  concrete  wai 
mixed  in  the  proportions  of  i  part  Atlas  Portland  Cement,  2  parts  sand 
and  4  parts  i-inch  screened  broken  stone,  while  for  the  abutments  and  wing 
walls  the  proportion  was  1 13:6  with  i*/2-inch  stone  and  for  the  spandrel  walls 
1  *3  -'5,  with  i-inch  stone. 

The  main  reinforcing  for  the  arch  consists  of  i*4-inch  curved  round  rods 
in  both  intrados  and  extrados  placed  about  four  inches  from  the  upper  and 

30 


lower  surfaces.  In  the  intrados  they  are  spaced  12  inches  apart  at  the  spring- 
ing line  and  extend  5  feet  past  the  center,  thus  giving  a  spacing  of  6  inches  for 
32  feet  at  the  crown.  In  the  extrados  they  are  12  inches  apart  at  the  abut- 
ments and  carry  2*4  feet  beyond  the  center  line,  thus  giving  a  5  foot  lap  for 
bond.  At  the  haunches  auxiliary  rods  about  26  feet  long  are  placed  in  all  the 
spaces  between  the  main  rods.  Above  and  below  both  the  intrados  and  ex- 


L&J 

Wa  terproof/n 
6 tone  ballast 


HALF  ELEl/. 


FIG.  5.— JACKSON^STREETiARCH,  C.  R.  R.  OF  N.  J. 

trades  rods,  horizontal  transverse  ^4-inch  rods  are  spaced  24  inches  apart  and 
extend  the  full  length  of  the  arch. 

In  designing  the  bridge  the  stress  in  the  arch  ring  was  computed  by  the 
graphical  method  of  Prof.  W.  A.  Cain,  the  live  load  assumed  being  the  stand- 
ard loading  of  the  Central  Railroad  of  New  Jersey  or  700  pounds  per  square 
foot  of  surface  while  the  dead  load  was  figured  as  follows :  Rails,  ties,  ballast, 


140  pounds  per  square  foot  of  surface;  filling,  100  pounds  per  cubic  foot,  and 
concrete,  160  pounds  per  cubic  foot.  Including  temperature  stresses  the  max- 
imum stress  in  the  concrete  was  600  pounds  per  square  inch  compression  and 
50  pounds  per  square  inch  shear,  while  the  maximum  stress  in  the  steel  was 
18,000  pounds  per  square  inch  in  tension  and  5,000  pounds  per  square  inch  in 
compression,  the  latter  value  being  fixed  of  course  by  the  permissible  stress 
in  the  concrete  times  the  ratio  of  elasticity  of  steel  to  concrete. 

During  the  construction  of  the  bridge,  railroad  traffic  was  maintained  un- 
interruptedly on  temporary  trestles  on  either  side  of  the  bridge. 


SIDE  ELEVATION 


8x8" 


5ECT/OA/  A'-'B' 


DETAIL  OF  WEDGE 

FIG.  6.— FORMS  FOR  JACKSON  STREET  ARCH. 

The  arch  forms  were  assembled  on  the  ground,  and  after  the  abutments 
were  well  under  way  they  were  swung  into  place  from  an  erection  car  on  the 
temporary  trestle.  The  photograph  in  Fig.  7  shows  the  method  of  placing 
these  centers.  The  concrete  in  the  abutments  and  the  filling  behind  them  was 
carried  to  a  point  about  2  feet  above  the  spring  line  of  the  arch,  when  the  arch 
ring  was  put  in  at  one  operation,  concreting  commencing  simultaneously  at 
the  springing  lines  of  both  abutments. 

The  concrete  was  mixed  in  a  i  cubic  yard  Ransome  Mixer  on  one  side  and 
a  i  cubic  yard  Smith  Mixer  on  the  other,  and  was  deposited  from  ordinary 
iron  wheelbarrows. 


With  the  exception  of  the  tops  of  the  spandrel  and  wing  walls,  which  were 
finished  with  a  i-inch  trowelled  surface  of  cement  mortar  applied  simultane- 
ously with  the  last  course  of  concrete,  the  finish  of  the  concrete  was  obtained 
by  simply  spading  back  the  concrete  from  the  forms. 

The  upper  surface  of  the  arch  is  waterproofed  with  four  coats  of  Hydrex 
felt  mopped  on  with  Hydrex  compound  applied  hot,  and  the  backfill  is  drained 
from  the  ends  of  the  abutments  by  two  6-inch  cast-iron  pipes  connecting  with 
the  city  sewer  in  the  center  of  the  street  as  shown. 

The  bridge  was  designed  by  the  engineering  department  of  the  railroad. 


FIG.  7.— SETTING  ARCH  'CENTERS. 

Mr.  J.  O.  Osgood,  Chief  Engineer,  and  was  constructed  under  their  super- 
vision in  the  spring  of  1904  by  Holmes  and  Coogan  of  Jersey  City. 

PAULINS  KILL  VIADUCT,  D.,  L.  &  W.  R.  R.  This  bridge,  under  con- 
struction in  1909,  is  approximately  noo  feet  long  and  115  feet  high  and  con- 
sists of  five  i20-ft  and  two  loo-ft.  reinforced  arches  with  skeleton  spandrel 
arches  supporting  the  track. 

The  drawings  in  Fig.  8  show  the  details  of  construction  of  a  typical  arch 
span  and  pier,  together  with  one  of  the  reinforced  abutments.  The  design  of 
the.se  abutments  furnished  a  rather  novel  and  economical  feature  inasmuch  as 

34 


Monho/e- 


35 


they  are  composed  of  three  longitudinal  reinforced  walls  carrying  a  reinforced 
slab  which  supports  the  track  and  ballast.  This  skeleton  construction  allows 
the  embankment  to  take  its  natural  slope  between  the  walls  as  well  as  on  the 
outside  of  them,  and  by  thus  balancing  the  earth  pressure  does  away  with  the 
bulky  section  which  would  have  been  necessary  had  they  been  designed  as 
retaining  walls. 

With  the  exception  of  the  copings  and  ornamental  railings,  which  are  of 
i  :2  14  proportions,  the  concrete  throughout  the  structure  is  mixed  in  the  pro- 
portions of  i  part  cement,  3  parts  sand  and  5  parts  broken  stone.  In  the 
abutments  and  piers  for  the  arches  and  foundations  below  the  ground  line,  large 
quarry  stones  are  bedded  in  the  concrete  so  as  to  form  a  rubble  concrete  and 
reduce  the  most  of  materials. 

In  designing  the  viaduct  a  ratio  of  elasticity  of  steel  to  concrete  of  15  was 
assumed  and  the  concrete  was  figured  at  600  pounds  per  square  inch  safe 
working  fiber  stress,  500  pounds  per  square  inch  direct  compression  and  50 
pounds  per  square  inch  shear,  while  the  steel  was  given  a  working  tensile) 
stress  of  16,000  pounds  per  square  inch. 

The  structure  was  designed  by  the  engineering  department  of  the  Dela- 
ware, Lackawanna  and  Western  Railroad  under  the  supervision  of  Mr.  Lincoln 
Bush,  Chief  Engineer,  with  Mr.  B.  H.  Davis,  Assistant  Engineer  in  charge 
of  masonry  design,  and  Mr.  F.  L.  Wheaton,  Engineer  of  Construction  in 
charge  of  work  in  the  field. 

VERMILLION  RIVER  BRIDGE,  C.,  C.,  C.  &  ST.  L.  RY.  In  its  essen- 
tial features  this  bridge  is  similar  in  type  and  design  to  the  Paulins  Kill  Via- 
duct illustrated  in  Fig.  8  and  consists  of  three  arches,  the  central  span  being 
100  feet  and  the  two  side  spans  80  feet,  with  rises  of  40  and  30  feet  respec- 
tively. 

The  photograph  in  Fig.  9  is  of  the  completed  structure,  while  Fig.  10  is  a 
view  taken  during  the  construction  showing  the  false  work  for  the  main  arches 
and  the  location  of  the  derricks. 

The  arch  rings  are  3^2  feet  thick  at  the  crown,  deepening  out  toward  the 
spring  lines,  and  are  reinforced  near  the  extrados  and  intrados  with  i-inch  cor- 
rugated bars  12  inches  apart  and  overlapped  4  feet  at  their  ends,  thus  giving 
a  bond  of  40  diameters.  Below  these  rods  at  the  extrados  and  above  them  at 
the  intrados  there  is  a  series  of  ^g-inch  transverse  bars  33  feet  long. 

Above  the  arch  rings  of  the  main  arches  the  channel  piers  are  hollow,  the 
pilasters  being  carried  up  as  reinforced  facing  slabs  15  feet  wide  and  3^2  feet 
thick.  The  transverse  walls  are  formed  by  the  piers  of  the  spandrel  arches 
next  to  the  springings,  which  have  brackets  at  the  top  projecting  12  inches  on 
the  inside.  These  brackets  carry  reinforced  concrete  slabs  2  feet  thick,  which, 

36 


37 


being  freely  supported  on  rails  embedded  in  the  tops  of  the  piers  and  bearing 
against  similar  rails  projecting  from  the  underside  of  the  slabs,  act  as  expan- 
sion joints.  A  similar  transverse  expansion  joint  is  placed  over  the  top  of 
each  abutment. 

The  concrete  in  these  joints  was  made  as  smooth  and  flat  as  possible  and 
finished  so  that  contact  between  the  adjacent  faces  at  the  point  is  made  only 
through  the  embedded  rails.  To  further  separate  the  division  two  layers  of 
felt  are  placed  between  the  two  surfaces  of  concrete  and  carried  up  to  within 


FIG.  10.— FALSE  WORK  FOR  MAIN  ARCHES. 

2  inches  of  the  top  of  the  vertical  joints,  the  remaining  space  being  filled  with 
asphalt. 

The  concrete  for  the  reinforced  portions  was  mixed  in  the  proportions  of 
i  part  cement  to  2  parts  clean  sand  to  4  parts  of  broken  stone;  that  for  the 
abutments  and  main  piers  of  1 13 :6  and  the  footings  of  1 14 :8  proportions. 

The  bridge  was  designed  in  the  construction  department  of  the  Cleveland, 
Cincinnati,  Chicago  and  St.  Louis  Ry.  and  was  built  by  the  Bates  and  Rog- 
ers Construction  Company  of  Chicago  in  the  fall  of  1905. 

WALLKILL  RIVER  VIADUCT,  E.  &  J.  R.  R.     This  is  a  very  heavy 

38 


unreinforced  concrete  bridge  388  feet  long,  having  a  width  of  32  feet  between 
outside  of  parapet  walls,  and  consists  of  four  6o-ft.  and  two  40-ft.  circular 
arches.  The  photograph  in  Fig.  3,  page  29,  is  of  the  finished  structure,  while 
the  drawings  in  Fig.  n  show  the  plan,  elevation  and  section  of  the  6o-ft. 
arches,  together  with  details  of  the  expansion  joints,  which  occur  at  each  pier, 
extending  from  the  top  of  coping  to  top  of  haunch.  The  starkweather  is  also 
drawn  in  detail. 

The  bridge,  which  contains  7500  cubic  yards  of  concrete,  was  designed  by 


E LEV  ATI/ ON 
B  (Leod  P/ate 


SECT/ON  A-B      SECTION  CO 


EXPANSION  JO/ NT 


18" 


Head 
p/ate 


Countersunk 

far 


A-B 


STEEL  $//0£ 


PLA/V 


FIG.  H.— DETAILS  OF  60-FT.  ARCH,   WALLKILL  RIVER  VIADUCT. 

the  engineering  department  of  the  Erie  Railroad  under  the  supervision  of  Mr. 
F.  L.  Stuart,  Chief  Engineer,  and  was  built  by  Lathrop,  Shea  and  Kenwood 
Company  of  Scranton,  Pa. 

GIRDER  BRIDGES. 

When  constructed  of  concrete,  girder  bridges  are  designed  either  as  entire 
reinforced  concrete  structures  or  as  a  combination  of  structural  steel  and  rein- 
forced concrete.  In  the  latter  case  the  main  girders  and  cross  beams  are  gen- 
erally composed  of  structural  shapes  encased  in  concrete  with  the  floor  slabs  of 
reinforced  concrete.  An  example  of  the  former  type,  which  contains  a  number 


39 


Co/umn  Re/nforcement   4-34X3£'x£ Is 

Wound  w//h  A/o.//r//qf?  carbon  stee/  w/re 

" wrap  or  2  tr/anqu/or  mesri  dm  <S.<£.  W  Co. 
/Vo./Z  &/4 


of  advanced  and  novel  features,  is  described  below,  while  the  First  Avenue 
Viaduct  described  on  page  57  is  an  interesting  example  of  the  latter  type. 

Among  the  miscellaneous  photographs  in  the  back  of  the  book  are  shown 
other  girder  bridges  of  both  types. 

In  designing  reinforced  concrete  girder  bridges,  care  should  be  taken  to 
see  that  there  is  sufficient  concrete  and  steel  provided  for  shearing  stresses,  as 
with  short  spans  and  heavy  loads  this  will  be  found  in  many  cases  to  be  the 
determining  factor. 

TRACK  ELEVATION  WORK,  CHICAGO,  ILL.,  C,  B.  &  Q.  R.  R.  In 
connection  with  the  track  elevation  work  which  the  Chicago,  Burlington  & 
Quincy  Railroad  is  carrying  on  between  Canal  Street  and  Blue  Island  avenue, 
Chicago,  there  are  a  number  of  reinforced  concrete  girder  bridges  forming 
subways  similar  in  type  and  design  to  the  drawings  shown  in  Fig.  12.  These 


•2 ft:  9 


PLAM  Or  r FT- O   STREET  SLAB 


-U 


£-*r/L.^Z  'I, 

—  24ft,/i-  f| 


&/A 


DETA/L  OFST/RHUP 


SECT/O/V 
FIG.  13.— DETAILS  OF  TYPICAL  SLAB,  C.,  B.  &  Q.  R.  R.  TRACK  ELEVATION. 

bridges  are  notable  because  of  their  extremely  large  size  and  capacity  and 
for  their  methods  of  construction.  As  will  be  seen  from  the  drawings  in 
Fig.  12,  the  essential  features  of  design  and  construction  of  a  typical  bridge 
consist  of  reinforced  concrete  columns  and  cross  girders  cast  in  place  and 
carrying  reinforced  deck  slabs  which  were  moulded  in  sections  away  from  the 
bridge  site  and  when  properly  cured  were  transported  on  flat  cars  and  set  in 
place  by  a  wrecking  crane.  After  being  thoroughly  waterproofed  the  ballast 
and  track  was  laid  directly  on  these  slabs.  Fig.  13  shows  the  details  of  a  typi- 
cal slab. 

The  columns  and  cross  girders  are  composed  of  concrete  mixed  in  the  pro- 
portions of  one  part  cement  to  four  parts  pit-run  gravel.  The  columns  are 
reinforced  with  four  3^/2  by  3%  by  */£  inch  angles  hooped  spirally  with  high 
carbon  steel  wire.  The  girders  and  slabs  are  reinforced  with  corrugated  bars. 


QUARTER  SECT/O/V 


42 


Fig.  14  shows  the  forms  used  in  the  construction  of  the  girders  and  columns. 

The  slabs  were  built  along  both  sides  of  a  switch  track  in  one  of  the  railroad 
yards  near  the  city  limits  and  after  curing  ninety-days  were  picked  up  by  a 
locomotive  crane  and  placed  on  flat  cars  and  hauled  to  a  convenient  storage 
place  where  they  were  piled  three  high  until  required  at  the  bridge  site. 

Each  slab  was  built  in  a  separate  form  and  after  being  cast  was  wet  thor- 
oughly every  evening  for  two  weeks.  The  slabs  were  made  with  the  ends 
and  sides  battered  so  as  to  have  a  clearance  of  %  mcn  between  them  at  the 
bottom  and  i  inch  at  the  top  on  both  sides  and  both  ends.  These  spaces  were 


FIG.  15.— SETTING  CONCRETE  SLABS,  C.,  B.  &   Q.  R.  R.  TRACK  ELEVATION. 

filled  with  waterproofing,  thus  making  the  whole  bridge  floor  water  tight.  A 
mixture  of  one  part  cement  to  four  parts  gravel  was  used  in  their  construction. 
The  slabs  for  the  long  spans  contain  approximately  19.2  cubic  yards  of  con- 
crete and  weigh  36  tons  each. 

In  handling  and  setting  the  slabs,  a  loo-ton  locomotive  crane  equipped 
with  a  special  toggle  frame  was  used.  The  photograph  in  Fig.  15  shows  this 
crane  in  the  act  of  setting  one  of  the  long  span  slabs. 

This  work  is  designed  and  constructed  by  the  Engineering  Department  of 
the  railroad  under  the  supervision  of  Mr.  C.  H,  Ortlidge,  Bridge.  Engineer. 

43 


1 


: 

vo 

§ 


7t4 

»•>» 


A 


«« 

.g 


*>  * 

<3  Sf  :£  ^ 

.^^  °   § 

$  §  -s  s 

gc§^b 

ft^ 


o    <o 


^••8  c£  a 

us* 


§ 

^ 

»:>^ 
^ 


'.M7.: 

f^v1 
fi\. 

^V?:*1' 
.^'X- 

*•'"  $'•• 

'-•'.-i'--.' 


4-Ft.7"  — 


44 


THROUGH  GIRDER  BRIDGE,  C.,  B.  &  Q.  R.  R.— In  Fig.  16  is  shown 
the  cross  section  of  a  reinforced  concrete  double  track  through  girder  bridge 
of  20  feet  3  inch  skew  span,  which  is  of  interest  since  this  form  of  construction 
is  employed  to  good  advantage  where  the  headroom  is  limited  and  a  deck 
girder  could  not  be  placed.  It  will  be  seen  that  the  two  outer  girders  act  as 
parapets  and  that  the  ballast  is  laid  directly  on  the  suspended  floor  slab.  The 
photograph  in  Fig.  17  is  of  a  similar  type  of  construction  of  18  foot  skew  span. 

TRESTLES. 

Reinforced  concrete  is  being  used  for  trestles  of  every  class.  In  the 
majority  of  cases  these  are  conservative  and  safe,  but  a  few  of  the  designs 
along  the  lines  commonly  employed  in  steel  construction  with  very  high  bents 
are  considered  by  many  conservative  engineers  to  be  extreme. 

In  structures  of  this  type  the  utmost  caution  should  be  employed  in  the 
mechanics  of  design  to  see  that  all  parts  are  symmetrical,  that  the  column 
design  is  conservative  and  that  proper  provision  is  made  for  temperature 
stresses. 

While  the  cost  of  a  reinforced  trestle  is  greater  than  that  of  a  timber 
structure,  this  difference  is  often  more  than  offset  by  the  temporary  character 
and  the  danger  from  conflagration  of  the  latter  type.  As  compared  to  steel 
construction,  reinforced  concrete  is  generally  cheaper  and  possesses  the  addi- 
tional advantage  of  being  free  from  constant  inspection,  painting  and  general 
maintenance. 

A  number  of  very  long  and  high  trestles  have  been  constructed  during  the 
past  few  years  of  reinforced  concrete,  one  of  the  largest  being  the  Richmond 
and  Chesapeake  Bay  Viaduct  described  below. 

The  Chicago,  Burlington  &  Quincy  Railroad  are  changing  over  all  the 
wooden  pile  trestles  on  their  line  to  similar  reinforced  concrete  structures,  a 
typical  example  of  which  is  shown  on  page  22. 

A  number  of  other  reinforced  concrete  trestles  are  shown  among  the  mis- 
cellaneous photographs  at  the  back  of  the  book. 

RICHMOND  VIADUCT  OF  THE  RICHMOND  AND  CHESAPEAKE 
BAY  RAILWAY.— The  Richmond  and  Chesapeake  Bay  Electric  Railway 
enters  Richmond  over  a  reinforced  concrete  viaduct  2,800  feet  long,  ranging 
in  height  from  18  feet  at  either  end  to  70  feet  at  its  highest  point.  A  riveted 
steel  girder  viaduct  was  first  contemplated,  but  was  rejected  on  account  of 
the  high  initial  cost  and  cost  of  maintenance,  as  well  as  the  difficulty  of  double 
tracking  such  a  structure  should  it  become  necessary.  A  wooden  trestle  was 
then  planned,  and  some  of  the  timber  ordered  and  partially  delivered,  when 
considerations  of  fire  protection  as  well  as  the  necessarily  temporary  character 

45 


of  wood  construction  persuaded  the  company  to  adopt  a  reinforced  concrete 
structure. 

Bids  for  the  design  of  such  a  structure  were  then  called  for,  the  railroad 
company  submitting  only  the  general  location,  profile  and  prescribed  loads. 
Under  these  conditions  the  design  of  the  New  York  branch  of  the  Trussed 
Concrete  Steel  Company,  Mr.  B.  J.  Greenhood,  Engineer,  was  accepted  and  the 
contract  for  the  construction  of  the  viaduct  awarded  to  Mr.  John  T.  Wilson, 
of  Richmond,  Va. 


FIG.  18.— VIEW  AT  CURVE,  RICHMOND  VIADUCT. 

The  viaduct  was  designed  to  carry  a  75  ton  car,  54  ft.  long  on  four-wheeled 
trucks  placed  33  ft.  apart,  each  truck  consisting  of  two  axles  7  ft.  on  centers. 
In  computing  the  sizes  of  the  various  members  it  was  assumed  that  the  via- 
duct should  carry  its  dead  load  and  the  entire  live  load  plus  50  per  cent  of  the 
live  load  for  impact.  The  longitudinal  thrust  due  to  the  braking  of  trains  was 
assumed  as  20  per  cent  of  the  live  load.  At  the  curves,  overturning  moments 
were  allowed  for  at  the  rate  of  2  per  cent  for  each  degree  of  curvature.  Wind 
pressure  was  figured  at  30  pounds  per  square  foot  on  the  surface  of  train  and 
yiaduct. 

For  the  superstructure,  it  was  decided  to  use  concrete  mixed  in  the  pro- 

46 


portions  of  i  part  Atlas  Portland  Cement,  2  parts  granite  dust  and  4 
parts  f^-inch  crushed  granite,  and  in  the  footings  a  1 12^4  :5  mixture  of  the 
same  materials.  The  columns  were  designed  for  a  compressive  stress  of  500 
pounds  per  square  inch  on  the  concrete  and  6,000  pounds  per  square  inch  on 
the  longitudinal  reinforcing  steel.  In  designing  the  girders,  continuous  beam 
action  was  assumed  and  the  concrete  was  figured  at  600  pounds  per  square 
inch  extreme  fiber  stress  and  50  pounds  per  square  inch  shear,  while  the  steel 
was  given  a  tensile  stress  of  16,000  pounds  per  square  inch.  In  proportioning 
the  footings,  which  bear  on  either  hard  clay  or  compact  gravel,  a  bearing 


FIG.  19.— VIEW  FROM  GROUND,  RICHMOND  VIADUCT. 

value  of  3  tons  per  square  foot  was  figured  on  for  all  possible  stresses  includ- 
ing future  double  tracking.  Kahn  trussed  bars  were  used  as  reinforcing  for 
the  entire  structure. 

The  viaduct  is  comprised  of  a  system  of  girders  of  rectangular  cross  sec- 
tion varying  in  span  from  23  to  68  feet  supported  by  a  series  of  interbraced 
and  battered  bents  varying  from  14  to  70  feet  in  height.  The  general  features 
of  design  and  construction  of  the  different  types  of  cross  section  of  the  viaduct 
are  readily  understood  from  the  accompanying  drawings  shown  in  Fig.  20. 

As  will  be  noted  by  the  photograph  in  Fig.  19,  the  diagonal  bracing  which 

47 


is  generally  seen  on  structural  steel  towers  is  replaced  by  transverse  and 
longitudinal  struts,  the  intention  being  to  design  all  joints  and  all  members 
so  that  they  will  have  the  rigidity  to  withstand  bending.  Provision  has  been 
made  for  double  tracking  the  viaduct,  when  traffic  warrants  such  an  extension, 
by  building  the  footings  for  all  bents  over  20  feet  in  height,  with  an  offset  col- 
umn base  to  which  new  columns  can  be  attached  and  by  leaving  cored  holes 
in  the  girders  for  connecting  the  new  work.  Both  of  these  features  are  shown 
clearly  in  Fig.  20. 

Expansion  joints  have  been  provided  where  the  short  girders  rest  on  the 
column  brackets,  at  intervals  of  about  200  feet,  consisting  of  a  grooved  steel 
plate  on  top  of  the  bent,  on  which  a  planed  steel  plate  on  the  bottom  of  the 
girder  slides;  together  with  steel  toggle  connections  at  the  upper  part  of  the 
girder  which  prevent  any  tendency  to  turn  the  girder.  Fig.  21  shows  the 
details  of  construction  of  one  of  the  49  ft.  girders. 

An  idea  of  the  massive  proportions  of  the  trestle  can  be  obtained  by  a  study 
of  the  photographs  in  Fig.  18  and  Fig.  19. 

The  track  consists  of  80  pound  rails  spiked  to  8  x  8  inch  cross  ties  12  inches 
on  centers  which  are  notched  1^/2  inch  over  and  bolted  to  6  x  12  inch  sleepers 
embedded  in  and  attached  to  the  concrete  girders  by  means  of  anchor  bolts 
as  shown  in  Fig.  20.  On  the  curves,  heavier  sleepers  are  used  under  the  out- 
side rail  as  shown  in  Fig.  20  in  order  to  gain  the  necessary  outer  elevation. 

The  guard  rail  is  made  of  8  x  10  inch  hard  pine  notched  2  inches  between 
the  ties.  By  extending  every  fifth  tie  four  feet  beyond  the  concrete  girder  and 
covering  this  extended  tie  with  planking,  a  footway  40  inches  wide  is  provided. 
In  a  similar  manner  the  poles  for  carrying  the  trolley  wires  are  supported. 

Work  on  the  structure  was  started  in  the  spring  and  finished  in  the  fall 
of  1906. 

In  the  construction  of  the  viaduct,  one  mixing  plant,  transferable  from  one 
place  to  another,  consisting  of  one  No.  2j4  rotary  mixer,  hoisting  engine, 
elevator,  buckets,  etc.,  was  used.  After  the  erection  of  the  forms  the  columns 
and  struts  up  to  the  bottom  of  the  girders  were  poured  at  one  continuous 
operation.  The  column  forms  were  built  in  three  sides  forming  a  U-shape, 
and  the  fourth  side  built  up  in  sections  as  the  concrete  was  poured.  The 
girders  and  floors  were  also  put  in  at  one  operation. 

The  forms  were  made  of  2-inch  lumber  dressed  on  one  side,  supported  by 
falsework  consisting  of  a  4  by  4  inch  and  6  by  6  inch  timbers.  The  girder 
sides  were  removed  at  the  end  of  a  week  while  the  remaining  forms  and  sup- 
porting falsework  were  left  in  place  for  at  least  thirty  days.  After  the  re- 
moval of  the  forms  the  entire  surface  of  the  viaduct  was  given  a  finish  of  sand 
and  cement  applied  with  a  brush. 

48 


49 


CONCRETE  PILE  TRESTLES,  C.,  B.  &  Q.  R.  R.— These  trestles,  which 
replace  similar  wooden  structures,  possess  a  number  of  features  comparatively 
new  to  the  field  of  concrete  construction.  In  general,  the  construction  con- 
sists of  six  pile  bents  spaced  14,  15  or  16  feet  center  to  center,  and  with  an 
average  height  of  10  feet.  The  essential  details  of  design  and  construction 
are  shown  by  the  drawings  in  Fig.  21,  while  the  photograph  in  Fig.  20  shows 
a  typical  trestle. 


FIG.  22.— CONCRETE  PILE  TRESTLE,  C.,  B.   &   Q.  R.  R. 

Two  types  of  piles  are  used,  namely,  rectangular  cast  piles  and  Chenoweth 
rolled  piles.  The  cast  or  molded  rectangular  piles  are  made  in  lengths  up  to 
30  feet,  and  are  16  inches  square  at  the  top  with  4-inch  chamfers.  The  rein- 
forcement consists  of  eight  y2-inch  bars  wired  to  a  spiral  coil  of  wire  of  varying 
pitch.  The  Chenoweth  rolled  pile,  which  is  the  type  shown  in  Fig.  21,  is  cir- 
cular in  section,  16  inches  in  diameter,  and  is  reinforced  with  %-inch  cor- 
rugated bars  wound  spirally  with  a  ^/2-inch  mesh  No.  16  wire  netting. 

The  piles  are  driven  vertically  by  an  ordinary  railroad  pile  driver  with  a 
3,ooo-pound  hammer,  with  cushioned  cap,  falling  24  feet. 

The  piles  are  capped  by  deep  reinforced  concrete  cross  girders,  which  sup- 
port the  slab?  forming  the  floor  or  deck. 

5* 


Each  span  consists  of  two  reinforced  concrete  slabs  or  girders,  each  slab 
forming  half  the  width  of  the  floor  and  having  a  curb  wall  to  retain  the  ballast. 

For  trestles  of  over  5  or  6  feet  spans  in  length,  longitudinal  rigidity  is 
obtained  by  the  use  of  double  bents  at  suitable  intervals,  consisting  of  two 
rows  of  piles  carrying  a  single  cap  twice  the  usual  width. 


iin.  Hods  6/n.  Cth. 
I  in,  ffods 
in. 


Rods  <3/y 
ffoofs  /£/, 

iin.  Rods. 


SECTION  ON  A  A 


SECTION  OF  /4ft  DECK 


ifaMeshW6M\ 

e 

^n  [ 

1                / 

^ 

^^ 

~~\ 

V^- 

——  z:~3 



im.Corr.Bars     J6in.         4  in. 

COA/C/=?Er£    PILE 


£/se  double  pile  cap  every  51h.  span 


Spans   /4ft  J5ft  or!6Ft. 
GENERAL     ELEVATION     OF  'TRESTLE 

FIG.  21.— PILE  TRESTLE,  C.,  B.  &  Q.  R.  R. 

In  the  first  of  these  trestles  to  be  built,  a  solid  pier  was  used  in  place  of  the 
piles  and  cap  at  every  sixth  bent,  but  the  double  bent  construction  is  now 
considered  preferable. 

The  deck  slabs  are  cast  in  the  railway  company's  yards,  and  after  season- 
ing about  sixty  days  are  carried  to  the  bridge  site  and  placed  in  a  similar  man- 
ner to  the  deck  girder  slabs  described  on  page  41.  The  ballast  and  track  are 
laid  directly  on  these  slabs. 


Different  proportions  of  concrete  are  used  for  different  parts  of  the  trestle. 
The  concrete  for  the  piles  is  mixed  in  the  proportions  of  one  part  cement  to 
three  parts  fine  screened  gravel,  while  for  the  caps  and  girder  slabs  a  mixture 
of  1 14%  with  gravel,  or  1 12 14  with  sand  and  stone  is  used. 

In  constructing  these  trestles  traffic  is  not  interfered  with.  The  floor  of 
the  existing  timber  trestle  is  partly  dismantled  and  concrete  piles  are  driven 
to  form  bents  intermediate  with  the  old  timber  bents.  The  forms  for  the  caps 
are  then  put  in  place  and  filled,  the  concrete  being  allowed  to  set  about  thirty 
days.  Part  of  the  timber  trestle  is  then  torn  out  by  a  derrick  car  or  wrecking 
crane  and  the  girder  slabs  set  in  place. 


FIG.  22.— PIER  TRESTLE,  iC.^B.   &?Q.  R.  R. 

CONCRETE  PIER  TRESTLES.— Where  longer  spans  are  used  and 
where  the  trestles  cross  streams  in  which  floating  ice  is  apt  to  occur, 
thin  concrete  piers  are  used  in  preference  to  the  pile  bents.  The  photograph 
in  Fig.  22  shows  a  typical  structure  of  this  type  of  25  foot  spans.  The  piers 
are  carried  down  to  footings  on  a  solid  foundation  or  are  supported  by  wooden 
or  concrete  piles. 

These  trestles  are  designed  and  constructed  by  the  Engineering  Depart- 
ment of  the  railroad  under  the  supervision  of  Mr.  C.  H.  Cartlidge,  Bridge 
Engineer. 

53 


OVERHEAD  HIGHWAY  BRIDGES. 

Owing  to  the  deteriorating  influence  of  locomotive  gases  upon  the  under 
surface  of  bridge  floors,  the  construction  of  overhead  highway  crossings  is 
one  of  the  greatest  problems  which  railroad  engineers  are  called  upon  to  solve. 

There  are  numerous  cases  where  after  a  few  years  steel  girders  and  string- 
ers, even  when  presumably  protected  by  brick  arches,  have  rusted  to  one-half 
their  original  thickness,  thus  endangering  many  lives. 

Steel  girders,  when  unprotected,  have  to  be  painted  very  frequently,  and,  as 
the  accumulated  rust  formed  by  the  locomotive  gases  has  to  be  removed,  this 
is  a  much  more  expensive  operation  than  under  ordinary  circumstances.  To 
do  away  with  the  high  maintenance  expense  and  to  overcome  the  effect  of 
the  sulphurous  fumes  from  locomotives,  old  structures  are  being  encased  in 
concrete  and  new  ones  are  being  built  either  entirely  of  reinforced  concrete 
or  of  structural  steel  encased  in  concrete.  Bridges  thus  constructed  are  abso- 
lutely unaffected  by  ordinary  rust,  rot  or  fire,  and  can  be  designed  economically 
along  artistic  lines. 

The  Blairstown  Bridge,  described  on  page  55,  is  an  entirely  reinforced 
concrete  structure  which  is  particularly  commendable  on  account  of  its  light 
and  graceful  lines,  while  the  First  Avenue  Viaduct,  shown  on  page  56,  is  an 
interesting  example  of  an  overhead  highway  bridge  composed  of  structural 
steel  girders  and  cross  beams  encased  in  concrete. 

Other  overhead  highway  bridges  are  shown  among  the  miscellaneous  pho- 
tographs ajf  the  back  of  the  book. 

OVERHEAD  HIGHWAY  BRIDGE,  NO.  19.31,  D.,  L.  &  W.  R.  R.— As 
will  be  seen  from  the  drawings  in  Fig.  23,  which  show  a  half  elevation  and 
half  section  together  with  details  of  construction,  this  bridge  consists  of  two 
reinforced  piers  and  abutments  supporting  reinforced  girders  and  floor  slab. 
The  two  exterior  girders  are  built  with  the  bottoms  slightly  arched,  thus 
giving  the  bridge  the  appearance  of  being  a  light  arched  structure  of  graceful 
lines. 

The  roadway  wearing  surface  is  formed  by  a  two  inch  excess  of  concrete 
which  is  built  as  a  part  of  the  floor  slab.  A  mixture  of  i  cement,  2  sand  and 
4  broken  stone  was  used  throughout  the  structure  and  the  finish  obtained  by 
floating  the  green  concrete  with  water,  immediately  after  removing  the  forms, 
and  rubbing  with  wire  brushes. 

In  designing  the  bridge  a  ratio  of  elasticity  of  15  was  assumed  and  the 
concrete  was  figured  at  600  pounds  per  square  inch  fiber  stress,  500  pounds 
per  square  inch  compression,  and  50  pounds  per  square  inch  shear,  while  the 
steel  was  given  a  tensile  stress  of  16,000  pounds  per  square  inch  and  a  com- 
pressive  stress  of  7,500  pounds  per  square  inch. 

54 


/5ft  O- 


x" 

M555^ 

")                  X 
^      X           T  « 

•  -.  ! 

r^* 

^^^       ^ 

i«S 

;• 

^i^nk.kijit 

vK^N      g 

Sil 

il^l'L 

"UU? 

^ 

1-Ii'l 

,  3^1  'o^- 

& 
rt 

A 

0  ! 

'^o>*iv,i1l0>Q 

o\»bb    ^Q-01 

^     ^ 

£ 

!!lS'iS!'^«5 

08 

^> 

;J 

'  '•             o^V 

§1          ^ 

fc 

n  "Si1^  x.-Xj 

^  ^             k  *<  ^ 

^                     K4 

iV, 

SX5^^ 

?!«      sll 

^           Q 

% 

\> —  /5ft-4"- 


56 


The  bridge,  which  was  constructed  in  1909,  was  designed  by  the  engineer- 
ing department  of  the  Delaware,  Lackawanna  and  Western  R.  R.,  under  the 
supervision  of  Mr.  Lincoln  Bush,  Chief  Engineer,  with  Mr.  B.  H.  Davis, 
Assistant  Engineer,  in  charge  of  masonry  design,  and  F.  L.  Wheaton,  En- 
gineer of  Construction,  in  charge  of  work  in  the  field. 

FIRST  AVENUE  VIADUCT,  L.  I.  R.  R.— This  viaduct,  788  feet  long, 
carries  First  Avenue  over  the  tracks  of  the  Long  Island  Railroad  at  Bay 
Ridge,  Long  Island.  It  is  68  feet  10  inches  wide,  and,  as  will  be  seen  from 
Fig.  24,  showing  a  cross  section  of  the  viaduct,  is  divided  by  the  main  girders 


FIG.  25.— FILLING  PIER  FORMS,  FIRST  AVENUE  VIADUCT. 

into  two  roadways  23  feet  3  inches  wide  and  two  sidewalks  n  feet  2  inches 
wide. 

The  main  girders,  which  are  supported  for  about  half  the  viaduct  on  con- 
crete piers,  and  the  remainder  of  the  distance  on  steel  columns  and  girders,  are 
riveted  steel  plate  girders  encased  in  concrete  to  a  level  a  little  above  the 
roadway  and  sidewalk.  The  drawings  in  Fig.  24  show  the  manner  in  which 
these  girders  are  encased,  with  details  of  the  bolster  protection,  and  the  photo- 
graph in  Fig.  26  gives  a  view  of  the  encased  girders  from  below.  Fig.  24, 
mentioned  above,  gives  the  general  dimensions  and  essential  features  of  design 

57 


of  the  piers  and  footings,  while  the  photograph  in  Fig.  25  is  a  view  taken  of 
them  during  construction  and  shows  the  forms  in  place  and  the  method  of 
depositing  the  concrete. 

The  floor  system,  the  details  of  which  are  shown  in  Fig.  27  (see  below), 
consists  of  24  inch  80  pound  I-cross  beams,  n  feet  on  centers,  entirely  encased 
in  concrete,  carrying  a  reinforced  concrete  floor  slab.  Twisted  rods  are  used 
as  reinforcement. 

The  concrete  for  the  piers  was  mixed  in  the  proportions  of  i  part  Atlas 
Portland  Cement  to  3  parts  sand  to  5  parts  i*/2  inch  broken  stone,  and  for  the 
other  parts  of  the  structure,  in  the  proportions  of  1 12  14  with  3/4  inch  broken 
stone. 


s/* 

U  /    & 


-//  fi-2"- 


Grono//t/7/c 


/ft-O"cc 


*^**Wttr 


•-^-^.^L-^^-W-^tl 

'    n^>    ^*'mrw.3ars  6c.c. 

h 


W     C/ in  ton  Wire   C/otn  — fej 


-3-5i 


Wain  wr/qhf    Curb 
s2"Aspa/t 
if-/ "  B/nc/er 


k4^ 


/"Briefer 


Hocfs    /ft-2"cc 


rw   Hods  Tec 


Expanded  Me  to 
//  ft  -  O" 


FIG.  27.— DETAILS  OF  FLOOR  CONSTRUCTION,  FIRST  AVENUE  VIADUCT. 

Before  the  concrete  of  the  sidewalk  slabs  had  time  to  set,  a  granolithic 
finish  i  inch  thick  consisting  of  i  part  cement  to  2  parts  trap  rock  screenings 
was  applied  and  worked  until  it  became  an  integral  part  of  the  concrete  and 
had  a  dense  and  smooth  surface. 

The  pavement  for  the  roadways  consists  of  a  i-inch  binder  course  with  a 
2-inch  wearing  surface  of  asphalt. 

By  using  hangers  suspended  from  the  bottom  flanges  of  the  cross  beams, 
the  forms  for  the  floor  slabs  and  haunches  around  the  bottom  flanges  of  the 


59 


steel  beams  were  supported  without  the  use  of  shoring.  Fig.  28  shows  this 
method  of  construction  in  detail. 

The  forms  for  both  piers  and  floors  were  treated  with  car  journal  oil.  Im- 
mediately after  removing  the  pier  forms,  which  was  on  an  average  about  48 
hours  after  filling,  the  green  concrete  was  floated  with  water  and  rubbed  by 
carborundum  bricks. 

The  construction  plant  consisted  of  a  5-ton  locomotive  crane,  a  */a  cubic 
yard  mixer,  two  24-inch  gauge  cars  carrying  two  ^4  cubic  yard  buckets  and 
ordinary  iron  barrows. 


/4-"CfoC 


/£.  "Asphalt          I  "Binder 


/5£o/As  v5"6 

FIG.  28.— FORMS  FOR  FLOOR  SLABS. 


The  viaduct  was  designed  by  the  engineering  department  of  the  Bay  Ridge 
Improvement  Company  under  the  supervision  of  Mr.  L.  V.  Morris,  Chief 
Engineer,  and  the  concrete  work  was  done  by  W.  H.  Gahagan,  contracting 
engineer,  of  Brooklyn,  N.  Y.,  during  the  fall  of  1908  and  the  winter  and  spring 
of  1909. 


BRIDGE    FLOORS. 

Since  railroad  engineers  came  to  the  conclusion  a  few  years  ago  that  the 
most  satisfactory  form  of  bridge  floor  was  a  ballasted  solid  floor,  a  great  many 
types  of  wooden  and  steel  floors  have  been  tried.  The  best  of  these  floors 
have  been  very  expensive,  and  while  satisfactory  for  a  limited  time  have 
proved  comparatively  short  lived. 

A  number  of  railroads  throughout  the  country  have  designed  bridge  floors, 
using  reinforced  concrete  in  the  form  of  a  slab,  that  have  given  absolute  satis- 
faction. The  reinforced  concrete  slab  usually  rests  either  directly  upon  the 
top  flange  of  the  girders  when  used  for  a  deck  bridge,  or  upon  floor  beams  and 

60 


girders  when  used   on  a  through  bridge.     Both   types   are   illustrated,  the 
former  by  Fig.  29,  and  the  latter  by  Fig.  31. 

A  reinforced  concrete  bridge  floor  of  considerable  proportions, — being  in 
reality  a  railway  yard  supported  on  plate  girders — which  has  given  marked 
satisfaction  during  the  period  it  has  been  under  traffic,  is  described  on  page  62. 

C.,  B.  &  Q.  R.  R.  BRIDGE  FLOORS.— Fig.  29  shows  the  cross  section, 
including  construction  forms,  of  a  reinforced  slab  of  trough  section  used  by 


'.  Bars  3/n  Ctrs. 


12.   s/'n:  Bars  /2/n.  C/AS 


Bra/n  ho/e.  form 

FIG.  29.— CROSS  SECTION,  DECK  GIRDER  BRIDGE  FLOOR,  C.,  B.  &   Q.  R.  R. 

the  Chicago,  Burlington  &  Quincy  R.  R.  for 'deck  bridges.  The  photograph 
in  Fig.  30  shows  a  typical  deck  bridge  floor. 

The  concrete  slab,  which  is  Sy2  inches  thick,  has  the  outer  edges  inclined 
upward  at  an  angle  of  30  degrees  to  make  flanges  9  inches  deep  which  retain 
the  standard  ballast,  the  cross  ties  being  placed  in  the  usual  manner. 

Before  putting  in  the  ballast,  the  top  of  the  deck  is  painted  with  tar  paint 
composed  of  one  part  oil,  four  parts  cement  and  sixteen  parts  tar.  Drip  pipes 
are  placed  in  such  a  position  as  to  keep  the  drip  clear  of  the  iron  structure. 

61 


As  will  be  seen  from  the  cross  section  in  Fig.  29,  the  top  lateral  system 
and  the  top  angles  of  the  sway  brace  frames  are  lowered  clear  of  the  top 
flange  angles  of  the  girders  to  allow  the  forms  for  the  concrete  to  be  set  with 
greater  ease  and  to  be  supported  on  the  transverse  frames  and  lateral  angles. 
The  outstanding  flanges  of  the  vertical  web  stiffener  angles  in  the  girders 
are  punched  for  connecting  bolts  to  the  2  by  6  inch  knee  braces  of  the  concrete 
forms. 


FIG.  30.— DECK  GIRDER  BRIDGE  FLOOR,  C.,  B.  &   Q.  R.  R. 


Fig.  31  shows  a  typical  floor  of  a  through-girder  bridge.  The  reinforced 
slab  rests  upon  the  floor  beams  and  extends  up  to  form  curb  walls  against  the 
girder,  enclosing  the  gusset  plates.  The  slab  is  4^2  inches  thick  and  is  rein- 
forced transversely  with  ^2-inch  corrugated  bars  6  inches  apart  and  longi- 
tudinally with  ^/2-inch  bars  i  foot  apart.  These  floors  are  designed  by  the 
engineering  department  of  the  railroad  under  the  supervision  of  Mr.  C.  H. 
Cartlidge,  Bridge  Engineer. 

REINFORCED  CONCRETE  BRIDGE  FLOORS,  D.,  L.  &  W.  R.  R.— 

This  mammoth  bridge  floor,  81  by  349  feet,  containing  26,269  square  feet  of 
floor  space  is  shown  in  detail  in  Fig.  33.     The  concrete  is  mixed  in  the  pro- 

62 


//?.  Bars   /6Ft  7"  Jong    €/'/?,  C  to  C 
Alternate   bar<s  jbenf  u     a< 


FIG.  31.  -CROSS  SECTION,  THROUGH-GIRDER  BRIDGE  FLOOR,  C.,  B.  &   Q.  R.  R. 


' 


'  •      FIG.  32.— DECK  GIRDER  BRIDGE  FLOOR,  C.,  B.  &  Q.  R.  P 

63 


, 


portions  of  i  part  Portland  cement,  2  parts  clean 
sharp  sand  and  4  parts  1^/2  inch  broken  stone. 
The  top  layer,  which  acts  as  waterproofing,  con- 
sists of  a  i -inch  coating  of  mortar  composed  of 
i  part  Portland  cement  to  2^2  parts  sand  troweled 
smooth  on  top.  After  this  layer  had  thoroughly 
set  the  entire  surface  was  given  a  heavy  coat  of 
pure  cement  grout. 

The  floor  slab  is  designed  so  that  switches  and 
cross  overs  may  be  made  anywhere. 

In  the  construction  of  the  floor,  it  was  found 
that  the  economy  involved  as  to  material  and  la- 
bor resulted  in  a  saving  of  from  30  to  40  per  cent 
from  the  cost  of  steel  channel  floor  for  the  same 
purpose.  A  square  10  ft.  by  10  ft.  contains  3,704 
cubic  yards  of  concrete  and  718.4  pounds  of  steel, 
while  a  standard  channel  floor  composed  of  15- 
inch  channels  protected  by  4  inches  of  concrete 
would  contain  1,234  cubic  yards  of  concrete  and 
2,640  pounds  of  steel. 

This  floor  was  designed  by  the  engineering 
department  of  the  railroad  under  the  supervision 
of  Mr.  Lincoln  Bush,  chief  engineer,  and  Mr.  B. 
H.  Davis,  assistant  engineer  in  charge  of  masonry 
design. 


CHAPTER   IV. 

CULVERTS. 

Concrete  is  used  to  advantage  in  the  construction  of  all  classes  of  culverts 
from  the  small  pipe  to  the  large  reinforced  arch  and  box  types. 

On  account  of  its  greater  simplicity  and  the  less  expensive  abutments  re- 
quired, the  reinforced  flat  top  culvert,  with  abutments  of  reinforced  concrete, 
is  more  economical  for  short  spans  than  the  arch  type. 

The  variation  in  the  designs  of  the  different  railroads,  together  with  the 
fact  that  none  appears  entirely  satisfactory,  has  led  to  the  making  of  special 


FIG.  34.— 5  FT.  x  7  FT.  BOX  CULVERT,  C.,  B.  &  Q.  R.  R. 

designs  for  this  book.  The  drawing  in  Fig.  35  with  the  accompanying  original 
table  give  the  requisite  dimensions  for  reinforced  culverts  of  4,  6,  8,  10,  12,  14, 
1 6,  1 8  and  20  foot  spans. 

As  an  aid  to  the  design  of  concrete  arch  culverts,  without  reinforcement, 
a  committee  of  the  American  Railway  Engineering  and  Maintenance  of  Way 
Association  submitted  to  that  association  in  1908  a  composite  design  embody- 
ing a  combination  of  details  of  construction  of  plain  concrete-arch  culverts  with 
the  necessary  dimensions,  selected  from  the  standards  of  railroads  in  the 
United  States  and  Canada,  and  for  this  data  the  reader  is  referred  to  Bulletin 
No.  105  of  that  Society. 

63 


I, 

CQ 
1* 

fr 

^o, 

? 

^^ 

52 

<§ 
I- 

o 


'Ci'i 

-b  / 
S 

T] 
.*-ff 


& 

Horizontal  Bars  /*/->  I 
every  third  bar  benf^ 

\                                 coKM 

\\s 

To 

*•  

Jj  <o              ^ 

31 

0' 

'0- 

/»• ; 
.•o 

D'' 


k 

QJ 

<ot<M 


.0- 


•f^^v^jv:^,^*.  :'i:<-: 


v5+2T 


u 


FIG.  35.— TYPICAL  CULVERT  DESIGN. 
(See  opposite  page.) 

66 


CO 


,3 


CO 


.  \OO\N  \N\C<)\pO\Tj(  \00\00\00 

£  w\i-Ki-Ki-Kic\cc\i>\i-\i-!\ 


CO 


CO 


•siBq 

•    pauuopp  joj  'uiBip 

•S    98    PUB     uie'jd     JGJ 

•uiBtp  09  JSB9J  ;y 


rHeOrH 
THrHrH 


CO\CO\t>\t> 


\00\00 
r-Kr-K 


rH  rH  rH  iH  rH  CN  C4 


* 


P      3 

H3  CO 


• 


CO 


8JT 

CO 


« 


£W 


Ijf 


CO 


CI\C-1  \OJ\pl  \CI\7t  \CI\TI 


•sj»q 
'tUBip 


.S    98    PUB 

•uiBip  OS  JSB8I  W 


-•  CM   CO 

.SrHiH 


t-OOOJOOt-CD 


.S 


TH  rH  rH  rH  rH  iH  09 


CN  CO  ^  tO  «D  t-  00  0> 


.3« 

•s- 


a« 

as 


^ua 

i< 


II 


ja  o 


o^2 

-w  d 
^a  « 
.5?S 

II 

ai 


*^  w 

s.l 
is. 

BB.S 

•Sg 

J'43 
£ 
r» 

Sg'P 

-H*s 

OT    .      O 

Isl 


Sgw 

M*0^.1 

8«9 

SSI 

s§^ 

w  o-o 

!i! 

3  O  C8 

si: 

fll 
iaj 

O     0 

fc     o 


DIMENSION  AND  REINFORCEMENT  FOR  CULVERTS  FROM  4  TO  20  SPAN. 
(See  Fig.  35,  page  66). 

67 


EXAMPLES  OF  CULVERT  CONSTRUCTION. 


IFt.S" 


Slope/ktol 


Grade,  not  /ess  than 
Sin.inJZFt  If 
conditions  permit. 


0/d  nails 

Catch  Basin  3  ft* 2. Ft.  deep  for 

/on_g  culverts   of  >sma// *S/X<B 

END  ELEVATION  &ECT/OA/ 

FIG.  36.— STANDARD  PIPE  CULVERT,  WING  TYPE,  N.  Y.  C.  &  H.  R.  R.  R. 


JftQ" 


fta/'/s 


FIG.  37.— STANDARD  PIPE  CULVERT,  STRAIGHT  TYPE,  N.  Y.  C.  &  H.  R.  R.  R. 

STANDARD  PIPE  CULVERTS,  N.  Y.  C.  &  H.  R.  R.  R.— Fig.  36  shows 
the  standard  pipe  culvert  of  the  wing  type  and  Fig.  37  the  standard  pipe  cul- 
vert of  the  straight  type  of  the  New  York  Central  &  Hudson  River  Railroad. 
In  both  types  the  footings  of  the  end  walls  are  composed  of  1 14  :yj4  concrete, 
the  main  body  of  the  walls  of  1 13 :6  concrete,  while  the  copings  are  mixed  in 
the  proportions  of  1 12 14. 


68 


STANDARD  3-FOOT  ARCH  CULVERT,  D.,  L.  &  W.  R.  R.— In  Fig.  38 
is  shown  a  cross-section  of  the  standard  3-foot  semicircular  arch  culvert  for 
75-feet  fills  on  the  Delaware,  Lackawanna  &  Western  Railroad.  As  will  be 
seen  from  the  cross-section,  the  invert  is  reinforced  with  3^-inch  bars,  12 
inches  on  centers  transversely,  and  2  feet  on  centers  longitudinally,  while  the 
arch  itself  is  reinforced  in  a  longitudinal  direction  with  3^-inch  bars  18  inches 
on  centers.  In  case  rock  or  shale  is  found,  the  invert  reinforcement  is  left 
out,  and  the  concrete  in  the  invert  reduced  to  a  thickness  of  one  foot  through- 
out. In  the  body  of  the  culvert  there  are  0.628  cubic  yards  of  1 12 14  concrete 
per  linear  foot. 


.  /&/'/?  CtoC 

Con  s  tru  cf/on 
Uoint 


in  Bars  2.Ft.CtoG 


.3       ° 

j?//7.  Bars  /<2  In.  CfoC 

O.628  Cu.JJcKs.per 


/inea/  foot 

FIG.  38.-  CROSS  SECTION,  3-FOOT  CULVERT,  D.,  L.  &  W.  R.  R. 


INDIAN  CREEK  CULVERT,  K.  C.,  M.  &  O.  RY.— The  drawings  in 
Figs.  39  and  40  give  the  essential  features  of  design  and  construction,  while 
the  photographs  in  Figs.  41  and  42  show  the  finished  culvert  before  and  after 
filling.  As  will  be  seen  from  the  drawings,  this  is  a  reinforced  box  culvert 
14  by  15  feet  and  about  250  feet  long.  An  interesting  feature  in  the  design 
of  the  culvert  is  the  use  of  reinforced  struts  spaced  8  feet  on  centers  instead 
of  a  solid  concrete  invert. 


69 


~f 


o  0(0  c  o  c4^7^^^::K4^:fe 


FOUNDATION    PLAN 

FIG.  39.— PLAN  AND  ELEVATION,  INDIANiCREEKiCULVERT. 

70 


! 


Ift  the  construction  of  the  culvert,  the  concrete  was  mixed  in  the  propor- 
tions of  i  part  cement  to  3  parts  Kansas  River  sand  to  5  parts  crushed  lime- 
stone, passing  a  2-inch  ring  and  freed  from  dust  by  screening.  The  mixing 
was  done  by  a  No.  i  Rotary  mixer.  The  forms  were  constructed  of  i-inch 
lumber  with  2  by  6-inch  studs  12  inches  on  centers.  All  excavation  and  pile- 
driving  was  performed  and  the  reinforcing  bars  furnished  by  the  railroad 
company,  who  also  bore  one-half  the  cost  of  keeping  the  foundations  dry 
while  the  forms  were  being  built  and  the  concrete  placed. 

The  following  figures*  give  the  unit  cost  to  the  contractor  and  the  unit 


/"Corr. 
Zven/d^Bar  Turned  Up/ 


\U  LJ '  - 


-4-fte1 

/"Corr.Bar-3  in  Each}  Strut 

24-"hftde'  Q  ft  C  toC 


7VO/V 

FIG.  40.—  CROSS  SECTION,  INDIAN  CREEK.  CULVERT. 

cost  to  the  railroad  company,  who  let  the  contract  on  the  basis  of  $9.00  per 
cubic  yard.  The  costs  given  covered  all  labor  and  materials  necessary  other 
than  the  exceptions  mentioned  above  : 


*W.  W.   Colpitts  in   "Railway  Age,"  Aug    2,   1907,   p.  143. 


Unit  Cost  to  Contractor. 

Cement $1.37  per  cubic  yard  of  concrete 

Sand    0.34     "        "         "       " 

Stone 1. 10     "        "         "       " 

Labor 2.48     "        "         "       " 

Lumber    0.76     "        "         "       " 

Miscellaneous 0.18     "        "         "       " 

"$6.23 

Unit  cost  to  Railroad. 

Excavation,  pumping,  etc $1.84  per  cubic  yard  of  concrete 

Piles  (389)  8,647  linear  ft 2.71     "        "         "       " 

Reinforcing  bars,  113,600  Ib.  .  .  .   2.56     " 

$7.11 

Total  unit  net  cost,  not  in- 
cluding  profit $13-34  Per  cubic  yard 


FIG.  41.— INDIAN  CREEK  CULVERT  BEFORE  FILLING. 
72 


The  culvert  was  designed  by  Mr.  W.  W.  Colpitts,  Assistant  Chief  Engineer 
of  the  Kansas  City,  Mexico  &  Orient  Railway,  and  was  built  by  Mr.  L.  J. 
Smith,  General  Contractor,  of  Kansas  City,  in  the  fall  of  1905. 


'•  --r^r  ii^^^^^t * 

^smms^^s- 


:  f  - 


FIG.  42.— INDIAN  CREEK  CULVERT,  K.  C.,  M.  &  O.  RY. 

EIGHTEEN  FOOT  ARCH  CULVERT,  BANGOR  &  AROOSTOOK 
R.  R. — The  drawing  in  Fig.  43  and  the  photograph  in  Fig.  44,  page  74,  are  of 
an  1 8-foot  arch  culvert  on  the  Bangor  &  Aroostook  R.  R.,  of  very  simple  and 
at  the  same  time  artistic  lines.  An  interesting  feature  of  the  design  of  this 
culvert  is  the  method  employed  to  protect  the  soil  under  the  culvert  from  wash 
or  undertow.  This  is  done  by  extending  the  paving,  which  is  of  concrete  with 
a  minimum  thickness  of  one  foot,  to  the  ends  of  the  wing  walls,  where  it  makes 
a  vertically  downward  return  to  the  depth  of  the  bottom  of  the  foundation 
5  feet  below  the  bed  of  the  stream  or  top  of  paving. 

The  concrete  was  mixed  in  the  proportions  of  one  part  Atlas  Portland 
Cement  to  3  parts  sand  to  6  parts  gravel,  and  cost,  everything  included, 
$6.4254  per  cubic  yard. 

The  culvert  was  designed  and  constructed  by  the  engineering  department 
of  the  Bangor  &  Aroostook  Railroad  in  1904  under  the  supervision  of  Mr. 
Moses  Burpee,  Chief  Engineer. 


73 


HALF  END  ELEVAT/ON  HALF    SECTION 

FIG.  43. — CROSS  SECTION  OF  18-FT.  CULVERT,  BANGOR  &  AROOSTOOK  R.  R. 


FIG.  44.— EIGHTEEN  FOOT  CULVERT,  BANGOR  &  AROOSTOOK  R.  R., 

74 


THIRTY  FOOT  CULVERT,  C.,  M.  &  ST.  P.  RY.— This  culvert,  which 
is  shown  by  the  photograph  in  Fig.  45,  is  of  interest  owing  to  the  fact  that  it 
serves  as  a  footing  for  trestle  bents  as  well  as  a  culvert.  As  will  be  seen  from 
the  accompanying  picture,  footings  are  built  upon  the  back  of  the  arch  on 
which  two  of  the  trestle  bents  rest.  The  culvert,  which  is  near  Farson,  Iowa, 
was  designed  and  built  by  the  Engineering  Department  of  the  Chicago,  Mil- 
waukee and  St.  Paul  Railway,  under  the  supervision  of  Mr.  C.  F.  Loweth, 
Engineer  and  Superintendent  of  Bridges  and  Buildings,  in  1908. 


FIG.  45.— THIRTY  FOOT  CULVERT,  C.,  M.  &  ST.  P.  RY. 


HORSESHOE  CULVERT.— The  photograph  in  Fig.  46,  page  76,  is  of 
special  interest,  as  it  shows  a  rather  unique  and  very  efficient  form  of  heading 
for  culverts  where  the  slope  of  the  embankment  is  not  particularly  steep.  In- 
stead of  perpendicular  end  walls,  a  horseshoe  heading  is  formed  by  cutting 
the  barrel  of  the  culvert  to  conform  to  the  slope  of  the  fill  and  by  forming  a 
shoulder  over  the  crown  to  hold  the  toe  of  the  slope.  The  culvert  is  at  Run- 
nells,  Iowa,  and  was  designed  and  built  by  the  N.  M.  Stark  Bridge  Company 
of  Des  Moines,  Iowa. 

75 


FIG.  46.— HORSESHOE  CULVERT,  RUNNELLS,  IOWA. 


FIG.  47.— DOUBLE  ARCH  CULVERTS,  ILL.  CENTRAL  R.  R. 
76 


CHAPTER  V. 


PIERS  AND  ABUTMENTS. 
PIERS. 

Concrete  is  employed  for  bridge  piers  either  as  filling  for  ashlar  or  cut 
masonry,  or  for  the  entire  pier,  in  which  case  it  may  be  of  either  plain  or  rein- 
forced concrete.  When  of  plain  concrete,  the  sizes  and  general  proportions 
are  practically  the  same  as  for  stone  piers,  the  quantity  of  masonry  used  for 
the  two  not  differing  materially.  If  reinforced  concrete  is  used,  there  may  be 
quite  a  saving  of  concrete  with  a  corresponding  reduction  in  the  cost  of  the 


FIG.  48.-  CONCRETE  PIERS,  PATERSON  AND  SUFFERN  RY. 

structure.  This  is  obtained  either  by  reducing  the  size  of  the  pier  or  by 
using  the  ordinary  size  of  pier  and  making  it  hollow  with  reinforced  walls,  in 
which  case  the  open  space  is  either  filled  with  sand,  broken  stone  or  gravel,  or 
if  the  pier  is  designed  so  that  it  possesses  sufficient  stability  it  is  left  open, 
thus  making  a  considerable  reduction  in  the  load  on  the  foundation.  The 

77 


top  slab  forming  the  coping  is  designed  strong  enough  to  support  the  loads 
brought  upon  it  and  transmit  them  to  the  side  and  interior  walls,  which  in  turn 
carry  the  loads  to  the  foundation.  Fig.  52  shows  the  design  of  a  typical  rein- 
forced pier. 

Concrete  is  also  used  very  advantageously  in  raising  the  grade  of  old  ma- 
sonry piers,  as  is  very  often  necessary,  an  interesting  example  of  which  is  de- 
scribed on  page  79. 


- 


FIG.  49.— CONCRETE  PIERS  DURING  ICE  JAM,  C.  R.  R.  OF  N.  J. 

STANDARD  PIERS,  N.  Y.  C.  &  H.  R.  R.  R.— The  standard  pier  of  this 
railroad,  adapted  to  any  height  up  to  40  feet,  is  shown  by  the  drawing  in  Fig. 
50.  The  width,  which  is  dependent  upon  the  length  of  span,  is  as  follows : 

Spans    up  to    40  feet  width,  A,  =  4  feet  o  inches 

Spans    40  to    60  feet  width,  A,  =  4  feet  6  inches 

Spans    60  to    80  feet  width,  A,  =  5  feet  o  inches 

Spans    80  to  100  feet  width,  A,  =  5  feet  6  inches 

Spans  100  to  125  feet  width,  A,  =  6  feet  o  inches 

Spans  125  to  150  feet  width,  A,  —  6  feet  6  inches 

Spans  150  to  200  feet  width,  A,  =  7  feet  o  inches 

Spans  200  to  250  feet  width,  A,  =  7  feet  6  inches 

78 


The  foundation  which  is  of  1 13 :6  concrete,  except  where  local  conditions 
make  stone  cheaper,  is  varied  to  suit  local  conditions,  but  is  not  less  than  4 
feet  deep  unless  good  rock  is  found.  The  pier  itself  is  constructed  of  i  :3 :6 
concrete  while  the  coping,  which  is  reinforced  with  galvanized  wire  netting  or 
wire  cloth  is  of  i  :i  12  concrete,  as  is  the  starkweather  cap  which  is  two  feet 
above  high  water.  The  charts  and  tables  in  Fig.  50  give  the  quantities  in 
these  standard  piers. 

/V-9Q  Ga/v.  w/re  rte-ffing  /"x2.  me-sh  or 
Clinton  Ga/v  wire  cloth  3"xQ"mesh  N°8wtre 
Base,   of  Rail 


Old  Hails  /OJo/Z'Ctrs. 
where  material  is  soft 
DOWN  STREAM  ELEV. 


f^5 

JDotted  line  v-sed  where 

not  necessary 

UP  STREAM 
ELEVATION 


!4-"/on_g 
/8"CfoC 
STAHKWATER 
PROTECTION 


For  Square  Crossings 


PLAN 


60 
60- »  80 
80"  "JOO 
100  »  -12.5 
»I5O 

>aoo 

2.00»»250 


FIG.  50.— STANDARD  PIER,  N.  Y.  C.  &  H.  R.  R.  R. 


»  »4-fJ.6" 
»  »5ft 


P/er-s  over  4-0  ft  ft i_gh  fo 
have  spec/a/ 


ti   fyf 

>>  »6Ft.6' 
»  »7Ft 
»  »7Ft.6' 


RAISING  GRADE  OF  OLD  MASONRY  PIERS.— The  photograph  in 
Fig.  51  shows  a  three  span  plate  girder  bridge  on  the  Chicago,  Milwaukee  and 
St.  Paul  Railway  which  originally  rested  on  piers  and  square  wing  abutments 
of  cut  stone  across  which  the  grade  was  raised  7^/2  feet  by  means  of  concrete. 
The  girders  were  raised  to  grade  and  the  concrete  built  in  place,  the  rounded 
ends  being  formed  by  means  of  steel  shells  held  in  place  by  rods  which  were 
left  in  the  concrete  to  give  additional  strength  to  the  piers.  A  short  span  was 
added  at  either  end  of  the  bridge  to  take  the  slope  and  a  rectangular  concrete 
pier  of  the  proper  height  to  bring  the  masonry  up  to  grade  was  built  on  each 
abutment. 


79 


FIG.  51.— RAISING  GRADE  OF  OLD  MASONRY  PIERS,  C.,  M.  &  ST.  P.  RY. 


REINFORCED  PIER,  K.  C.,  M.  &  O.  RY.— In  Fig.  52  is  shown  the  design 
of  a  standard  reinforced  concrete  pier  of  the  Kansas  City,  Mexico  &  Orient  Ry. 


FROMT  ELEV  &  SEC  T/O/V    EA/D  ELEV  &  <5EC. 

FIG.  52. — STANDARD  REINFORCED  CONCRETE  PIER,  K.  C.,  M.  &  O.  RY. 

80 


ABUTMENTS 

PLAIN  ABUTMENTS.  Abutments  for  bridges  can  be  designed  of  either 
plain  or  reinforced  concrete.  When  plain  concrete  is  used  the  general  details 
are  essentially  the  same  as  those  employed  for  stone  abutments.*  The  Van 
Cortlandt  Avenue  abutments  on  the  N.  Y.  C.  &  H.  R.  R.  R.,  described  on  page 
83  and  shown  in  plan,  elevation  and  section  in  Fig.  53,  are  fine  examples  of 
this  type,  not  only  as  to  details  of  construction,  but  also  on  account  of  the 
architectural  treatment  of  the  design. 

REINFORCED  ABUTMENTS.  By  using  reinforced  concrete  there  is 
generally  a  considerable  saving  in  materials  which  in  some  instances  has  been 
so  great  as  to  reduce  the  cost  as  much  as  40  per  cent. 

The  general  features  of  design  and  method  of  reinforcing  will  be  under- 
stood from  a  study  of  the  drawings  of  the  Third  Street  abutment,  K.  C.,  M. 
&  O.  Ry.,  shown  in  Fig.  56,  page  85.  It  will  be  seen  that  the  construction,  with 
the  exception  of  the  bridge  seat  and  supporting  buttresses,  closely  resembles 
that  of  reinforced  buttressed  retaining  walls  described  in  Chapter  VI. 

The  bridge  seat  consists  of  a  heavy  reinforced  concrete  slab  extending  over 
the  tops  of  the  supporting  buttresses,  thus  securely  knitting  the  structure 
together. 

These  supporting  buttresses  are  located  directly  under  the  bridge  girders, 
thus  eliminating  bending  in  the  slab  forming  the  bridge  seat.  In  designing 
the  buttresses  the  width  must  be  taken  at  least  equal  to  that  of  the  bed  plate. 

In  order  to  resist  the  overturning  moment,  vertical  bars  are  placed  in  the 
back  and  extend  through  the  base  hooking  under  the  horizontal  bars  in  the 
bottom.  A  sufficient  number  of  horizontal  bars  are  placed  in  the  buttresses 
as  shown  in  Fig.  56,  so  as  to  transfer  the  total  load  from  the  face  wall  to  the 
buttresses  without  depending  upon  the  tensile  strength  of  the  concrete.  The 
diagonal  shear  in  the  buttresses  is  taken  care  of  by  the  diagonal  rods  which 
hook  under  the  bottom  bars  in  the  rear  of  the  base  and  over  the  longitudinal 
bars  in  the  face  wall. 

A  face  wall,  heavy  enough  to  resist  the  earth  pressure  and  live  load  trans- 
ferred through  the  earth,  is  placed  in  front  of,  and  constructed  monolithic 
with,  the  buttresses,  the  two  being  firmly  tied  together  by  means  of  the  rein- 
forcing bars  with  hooked  ends.  This  face  wall  is  continued  beyond  the  bridge 
seats  to  form  wings,  and  is  supported  by  buttresses  at  intervals  of  about  8 
feet. 

At  the  back  of  the  bridge  seat  there  is  a  parapet  wall  forming  the  back  or 
mud  wall,  as  in  a  stone  abutment,  which  is  provided  with  returns  at  the  ends 


"The  design  of  abutments  for  arches  is  treated  in  Taylor  &  Thompson's  "Concrete 
Plain  and  Reinforced,"  Second  Edition,  1909,  and  in  Baker's  "Masonry  Construction," 


81 


82 


to  the  face  walls  and  is  supported  by  buttresses  similarly  to  the  front  wall,  and 
in  addition  by  the  vertical  bars  extending  into  the  bridge  seat. 

The  base  consists  of  a  rectangular  slab  sufficiently  reinforced  to  distribute 
over  the  foundation  the  load  transmitted  by  the  buttresses  under  the  bridge 
seat.  Usually,  as  is  the  case  in  the  design  mentioned  above,  the  width  of  the 
base  is  not  taken  less  than  one-half  the  height  of  the  abutment.  To  minimize 
the  eccentricity  of  the  load,  the  base  extends  about  two  feet  beyond  the  face 
wall. 


FIG.  54.— VAN  CORTLANDT  AVE.   ABUTMENTS,   N.  Y.  C.  &  H.  R.  R.  R. 

VAN  CORTLANDT  AVE.  ABUTMENTS,  N.  Y.  C.  &  H.  R.  R.  R.  These 
abutments,  which  were  designed  and  constructed  by  the  engineering  forces  of 
the  New  York  Central  Railroad  during  the  fall  of  1904,  are  noteworthy  exam- 
ples of  the  adaptability  of  concrete  to  architectural  treatment  in  structures  of 
this  nature,  which  are  frequently  crude  to  the  extreme. 

The  drawings  in  Fig.  53  show  the  essential  features  of  design  and  con- 
struction, while  the  photograph  in  Fig.  54  gives  an  idea  of  the  artistic  effect 
which  is  derived  from  the  moulded  pylons  and  the  graceful  lines  of  the  wing 
walls. 

In    the    construction    of    the    abutments    four    different    proportions    of 


83 


Atlas  cement,  sand  and  broken  stone  were  used  as  follows:  Footings 
1 14:7^;  main  wall  and  wing  walls,  1 13 :6;  bridge  seats  and  pylons,  i  :i  12,  and 
copings,  1 12 14. 

Old  rails  with  joints  staggered  and  bolted  together  with  two  angle  bars 
were  laid  in  the  footings  12  inches  on  centers  and  6  inches  from  the  bottom. 
The  bridge  seats  were  reinforced  with  Clinton  Galvanized  Wire  Cloth,  3  by  8 
inch  mesh  No.  10  wire. 

Each  abutment  is  provided  with  a  4-inch  cast  iron  down  spout  which  is 
hidden  in  a  6  by  8  inch  chase  in  the  center  of  the  face  of  the  wall  and  connects 
with  a  6-inch  tile  drain  on  one  side  and  discharges  into  the  gutter  on  the  other. 


FIG.  55.— THIRD  STREET  ABUTMENTS,  K.  C.,  M.  &  O.  RY. 

THIRD  STREET  ABUTMENTS,  K.  C.,  M.  &  O.  RY.  These  rein- 
forced concrete  abutments  are  on  the  Kansas  City  Outer  Belt  and  Electric 
Railroad,  which  furnishes  an  entrance  into  Kansas  City  and  terminal  facilities 
for  the  Kansas  City,  Mexico  and  Orient  Railway,  and  were  designed  by  Mr. 
W.  Colpitts,  Assistant  Chief  Engineer  of  the  road,  and  built  by  Mr.  L.  J. 
Smith,  general  contractor,  of  Kansas  City,  in  the  fall  of  1906. 

The  general  dimensions,  arrangement  of  reinforcing  and  principal  features 
of  design  are  shown  clearly  on  the  drawings  in  Fig.  56,  while  the  photograph 
in  Fig.  55  shows  the  finished  structure. 

84 


; 

*v~  ^*      -^"          _l 


FIG.  56.— THIRD  STREET  ABUTMENTS,  K.  C.,  M.  &  O.  RY. 

85 


With  the  exception  of  the  bridge  seats,  which  are  of  1  12  14,  all  the  concrete 
was  mixed  in  the  proportion  of  i  part  Portland  cement  to  3  parts  Kansas  river 
sand  to  5  parts  crushed  limestone,  passing  a  2-inch  ring  and  freed  from  dust 
by  screening. 

Seven-eighths-inch  corrugated  bars  were  used  for  reinforcing  throughout 
the  abutments  and  adjoining  retaining  walls.  All  bars  were  lapped  3  feet  with 
joints  broken.  The  supporting  piles  extend  6  inches  into  the  base  slab  and 
were  covered  with  three  inches  of  concrete  before  the  reinforcing  bars  were 
put  in  place.  In  both  abutments  and  retaining  walls  the  face  walls  were 
trenched  six  inches  into  the  base  slab. 

The  forms  were  constructed  of  i-inch  lumber  with  2  by  6  inch  studs  12 
inches  on  centers  and  the  concrete  was  mixed  by  a  No.  i  Rotary  Mixer. 

All  excavation  and  pile  driving  was  done  and  the  reinforcing  bars  fur- 
nished by  the  railroad  company,  who  also  bore  one-half  the  cost  of  keeping 
the  foundations  dry  while  the  forms  were  being  built  and  the  concrete  placed. 

The  following  figures*  give  the  unit  cost  to  the  contractor  and  the  unit 
cost  to  the  railroad  company  who  let  the  contract  on  the  basis  of  $9  per  cubic 
yard,  which  covered  all  labor  and  materials  necessary  except  the  items  under 
"unit  cost  to  railroad." 

:::Unit  cost  to  contractor: 

Cement  ...................  $1.78  per  cubic  yard  concrete 

Sand    .....................   0.35     " 

Stone    .........  .  ..........    1.35     " 

Lumber    ..................   0.74     " 

Labor    ....................   2.75     " 


Miscellaneous   .  .   0.16     " 


«  « 


$7-13 

Unit  cost  to  railroad: 

Excavation    (total) $3.80  per  cubic  yard  concrete 

Piles  (214)  5,228  lin.  ft 1.84     " 

Reinforcing  bars   1.82     " 

$7.46  " 

Total  unit  *  ost,  not  including 

profit $14-59     " 


86 


«  (( 


CHAPTER   VI. 


RETAINING  WALLS. 

The  use  of  both  plain  and  reinforced  concrete  for  retaining  wall  construc- 
tion in  track  elevation  and  depression  work  has  become  general  throughout 
the  country.  The  plain  concrete  walls  are  designed  of  gravity  section,  that  is, 
they  are  made  sufficiently  heavy  to  prevent  sliding  or  overturning  by  their 
own  weight.  Reinforced  walls  consist  either  of  a  thin  vertical  wall  attached 
to  a  horizontal  base  and  braced  either  by  counterforts  on  the  back  or  by  but- 
tresses on  the  front  side,  or  they  are  designed  as  cantilevers,  in  which  case  the 
wall  is  attached  to  a  spreading  base,  the  whole  section  being  in  the  form  of  an 
inverted  T. 

Reinforced  concrete  retaining  walls  usually  are  more  economical  than  plain 
concrete  walls,  since  in  the  latter  type  the  material  cannot  be  fully 
utilized  because  the  section  must  be  made  heavy  enough  to  prevent  overturn- 
ing by  its  own  weight.  In  reinforced  concrete  retaining  walls,  on  the  other 
hand,  a  part  of  sustained  material  is  used  to  prevent  overturning,  and  the  sec- 
tion need  be  made  only  strong  enough  to  withstand  the  moments  and  shears 
due  to  the  earth  pressure.  The  wall  is  lighter  and  exerts  smaller  pressure  on 
the  soil,  which  with  the  possibility  of  extending  the  base  of  the  wall  some- 
times enables  the  constructor  to  get  along  with  ordinary  foundations  in  cases 
where  for  masonry  walls  piles  would  have  been  indispensable.  They  also 
admit  the  use  of  a  more  scientific  design,  since  the  behavior  of  reinforced  con- 
crete is  even  better  known  and  more  reliable  than  that  of  plain  concrete. 

The  common  practice  among  railroad  engineers  of  using  arbitrary  ratios  ot 
width  of  base  to  height  of  walls  in  designing  retaining  walls,  leads  to  a  neglect 
of  the  study  of  the  distribution  of  the  pressure  on  the  foundation.  Since  it  is 
well  established  that  movements  from  the  original  alignment  due  to  unequal 
settlement  from  a  defect  more  common  than  any  other,  this  question  is  of 
great  importance  and  each  case  should  be  carefully  studied  and  the  amount 
and  distribution  of  the  pressure  on  the  bed  or  foundation  determined. 

Also,  by  a  careful  analytical  treatment,  the  most  effective  section  and  the 
minimum  amount  of  material  will  be  attained,  whereas  many  of  the  walls  thus 
far  designed  have  embodied  a  great  waste  of  material  with  a  resulting  lack  of 
economy  in  design. 

87 


Bars  P 


BcrrsM 

FIG.  57.— DESIGN  OF  T-SECTION  RETAINING  WALLS 


Horizon 
Bars 


ormed 
re  Ba 
M 


Def 


•a 


far 

CO 


far 

CO 


mensions 
of 
lab 


Sl 


1  +•>  fl 

ai  ««  1 

«  «j  2 

SSI 


N  a 


rtN  t-  t-O 

.9  iH  rH  CSJ  CO 


J  <N  0>  0  00 


TH  10  10  10 


.5  OS  IO  CO  iH 

IH  oq  eo 


.g'888 


Q        ^  <*  CO  00"  iH 

•OOtNCOO 
£         rH  tH  CM 

HC4CO<4< 
DIMENSIONS  AND  REINFORCEMENT  FOR  T-TYPE  RETAINING  WALLS. 


FIG.  58.— DESIGN  OF  COUNTERFORT  TYPEVQF  RETAINING  WALLS. 

go 


Spacing 


and 
Bar 


ed 


.M       juampaqmi 

M  ,«    ,TiS»T^^r 


einf 


2^ 

in  ctf 
g^ 


§* 


ssaujpiqx 


ssatnpiqx 


juauipaqrai 


*    d  °TH  °  C  o^ 
S^oogoo^wg 

rfjZ  \Q    3  OtT^J  «lT  S 

r\    r\     t\    tvt    ft    t)     t\    nt 


CO 


1C 


\N' 

rH\ 


TH         OS         iH 
CO        CO        •* 


_;     (N        •*        ^        ^ 
.5     rH         rH         r-l         rH 


•      TH         CD         CD         00 
.3     <N        <N        CO        00 


3zis        i  g 


eo 


•"•     **     ** 


10  rrj 

l>        CO 

•*'      id 


asBg  jo  qjSuaq          pq 


co      10      oo 


W     « 


CO 


ai3nB  jo 


q) 


'I 

9) 

43 

O 

u 

3 


— 


bi)S 


W 

r 


6° 
fc.S 


0,«D 


CO 


00 


COt-THOJCOt-THCOCOt-THt-OOOTH 


COt-THOJCOt-TH 
<NrHrH(N<NrHi-t 


2 


•°s 
92 


, 
O) 


w 


. 

.5  rH 
<N 


CO 


DIMENSIONS  AND  REINFORCEMENT  FOR  RETAINING  WALLS  WITH  COUNTERFORTS 


« 


ss 

:| 


2* 
^ 
ll- 

ri 


o-  .<c 
«  t3'5 


.«     .  b£-o 

»  a  c  c 

Ipi 

ill! 


Ill 


As  to  which  of  the  two  types  of  reinforced  concrete  retaining  walls  is  for  a 
specific  case  the  more  economical  depends  upon  the  height  of  the  wall,  the  in- 
tensity of  earth  pressure  and  the  relative  cost  of  concrete  and  steel.  As  a  gen- 
eral thing  the  construction  of  the  inverted-T  type  is  simpler  and  the  placing 
of  the  steel  easier,  requiring  less  skilled  labor  and  experience. 

The  least  height  at  which  the  counterfort  type  may  be  economical  has  been 
found  by  special  studies  for  this  chapter  to  be  in  general  about  18  feet. 

In  retaining  walls  of  any  considerable  length  it  is  necessary  to  provide 
against  shrinkage  and  temperature  cracks. 

The  general  practice  for  walls  of  unreinforced  concrete  is  to  place  contrac- 
tion joints  at  intervals  of  from  30  feet  to  50  feet.  It  is  possible  to  provide 
enough  horizontal  reinforcement  to  so  distribute  the  temperature  stresses  that 
the  cracks  will  be  very  minute  and  scarcely  noticeable.  For  this  0.3  per  cent 
of  horizontal  steel  based  on  the  vertical  section  of  the  wall  is  sometimes  used 
and  this  should  be  placed  near  the  surface  and  in  small  sized  rods.  It  is  quite 
common  practice  to  introduce  a  smaller  quantity  of  horizontal  reinforcement 
and  in  addition  provide  occasional  contraction  joints  to  allow  for  movement 
and  to  localize  any  cracking. 

In  constructing  retaining  walls  it  is  of  the  utmost  importance  that  careful 
attention  be  given  to  the  earth  filling  and  to  its  drainage.  The  drainage  is 
most  easily  accomplished  by  filling  close  to  the  back  of  the  wall  with  some  por- 
ous material  such  as  gravel,  crushed  stone  or  cinders  and  by  placing  weep  holes 
through  the  wall  at  suitable  distances  apart  to  carry  the  water  from  behind 
the  wall.  The  distance  apart  of  these  weep  holes  is  dependent  upon  local 
conditions,  and  should  be  decided  after  careful  examination  of  the  ground. 
The  standard  retaining  wall  specifications  of  a  number  of  railroads  call  for 
weep  holes  not  more  than  15  feet  apart  with  vertical  blind  drains  extending  to 
the  top  of  the  wall. 

It  is  not  within  the  scope  of  this  book  to  go  into  a  discussion  of  the  various 
methods  of  determining  the  pressure  exerted  on  retaining  walls  or  to  give  a  the- 
oretical treatment  of  the  designs  of  the  different  types  of  walls,  but  the  tables 
in  Figs.  57  and  58  give  the  necessary  dimensions  for  the  T-section  and  coun- 
terfort types  of  retaining  walls  for  heights  and  pressures  ordinarily  met  with. 
These  have  been  prepared  especially  for  this  book.  For  a  complete  analysis 
of  the  subject  of  concrete  retaining  walls  the  reader  is  referred  to  Taylor  and 
Thompson's  "Concrete,  Plain  and  Reinforced,"  second  edition,  1909,  and  to 
"Walls,  Bins  and  Grain  Elevators,"  by  Milo  S.  Ketchum. 

In  designing  the  walls  given  in  the  tables  referred  to  above,  the  earth 
pressure  was  computed  by  Rankine's  formula  for  a  fill  weighing  100  pounds 
per  cubic  foot  and  an  angle  of  repose  of  35  degrees.  The  filling  was  assumed 
as  sloping  behind  the  wall  at  the  angle  of  repose. 

92 


The  unit  stresses  assumed  were :  Compression  in  the  concrete,  500  pounds 
per  square  inch;  tension  in  the  steel,  16,000  pounds  per  square  inch;  shear  in 
the  concrete  involving  diagonal  tension,  40  pounds  per  square  inch;  bond,  80 
pounds  per  square  inch  for  plain  and  120  pounds  per  square  inch  for  deformed 
bars. 


FIG.  59.— BRONX  IMPROVEMENT  RETAINING  WALL,  N.  Y.  C.  &  H.  R.  R.  R. 

EXAMPLES  OF  RETAINING  WALLS. 

STANDARD  GRAVITY  RETAINING  WALL,  N.  Y.  C.  &  H.  R.  R.  R. 
Fig.  60  shows  the  cross  section  and  table  of  contents  per  running  foot  of  this 
type  of  wall.  The  concrete  below  the  ground  line  is  mixed  in  the  proportions 
of  1 14 :7^,  from  the  ground  line  to  the  coping,  in  the  proportions  of  1 13 :6,  and 
for  the  coping,  in  the  proportions  of  1 12 14.  Expansion  joints  filled  with  one 
layer  of  tar  paper  with  the  edge  %-inch  back  from  the  face  of  the  masonry  are 
provided  every  50  feet.  The  back  filling  consists  of  cinders  or  other  porous 
material  and  the  drainage  is  taken  care  of  by  4-inch  weep  holes  not  more  than 
15  feet  apart,  with  vertical  blind  drains  extending  to  the  top  of  the  wall.  Along 
side  walls  these  weep  holes  are  placed  9  feet  below  the  top  of  the  side  walls 
and  are  piped  to  the  gutter. 

The  photograph  in  Fig.  59  is  an  example  of  a  gravity  retaining  wall  on  the 
Bronx  improvement  work  carried  on  by  the  New  York  Central  and  Hudson 
River  Railroad. 

93 


Table  of  Contente 


He/jkf 

A 


a/// 


$-0 


JQ-O 


//-o 


/3-0 


3/-Q 


30-0 


o, 


FIG.  60.— STANDARD  GRAVITY  RETAINING  WALL,  N.  Y.  C.  &  H    R.  R.  R. 

REINFORCED  RETAINING  WALLS,  C.,  B.  &  Q.  R.  R.— Fig.  61  shows 
the  essential  features  of  design  and  construction  of  a  typical  track  elevation 
retaining  wall  of  the  Chicago,  Burlington  and  Quincy  Railroad,  which  is  in 
reality  a  compromise  between  the  plain  monolithic  and  the  cantilever  types  of 
walls.  In  designing,  no  attempt  was  made  to  use  the  full  compressive 
strength  of  the  concrete,  as  such  a  condition  would  have  required  a  much 
greater  amount  of  reinforcement  and  at  the  same  time  would  have  developed 
an  excess  of  strength  beyond  requirements.  Sections  at  the  top  of  the  foot- 
ing, at  the  angle  in  the  back  of  the  wall,  and  at  points  both  above  and  below 
this  angle  were  analyzed  and  the  stresses  computed  by  Prof.  Howe's  formulas 
and  a  sufficient  amount  of  reinforcement  was  provided  to  take  care  of  the  total 
tensile  strength  at  every  point  which,  however,  was  very  small  because  of  the 
comparatively  heavy  section.  Owing  to  the  difficulty  in  constructing  rein- 
forced abutments,  plain  concrete  was  used;  the  footings,  however,  have  a  re- 
inforced projection  in  front  to  increase  the  bearing  area.  As  a  general  thing 


94 


the  walls  are  supported  on  piles  closely  spaced  under  the  toe  and  more  widely 
apart  under  the  heel.  The  concrete  was  mixed  in  the  proportions  of  i  part 
cement  to  6  parts  pit  run  gravel. 

In  Fig.  62  are  shown  the  forms  used  in  constructing  these  walls,  together 
with  the  method  of  bracing  and  tying  down  the  forms.  They  comprise  a  com- 
bination of  continuous  and  sectional  forms,  the  sectional  portion  consisting  of 


4-in. 


FIG.  61.— CROSS  SECTION  TYPICAL  RETAINING  WALL,  C.,  B.  &   Q.  R.  R. 

studs,  coping  and  bottom  forms  for  the  face,  and  entire  sectional  forms  for  the 
back  of  the  wall. 

As  the  cross  section  of  the  wall  is  such  that  in  rilling  the  concrete  showed 
a  tendency  to  lift  the  forms  off  the  footing,  ^4-inch  bars  were  placed  in  the 
footing,  as  shown  in  Fig.  62,  and  the  forms  tied  to  them  with  wires.  The  wall 
forms  are  tied  together  by  3/£  rods  which  pass  through  pieces  of  2-inch  scrap 

95 


pipe  cut  to  fit  loosely  between  the  forms,  the  ends  of  the  pipes  being  stuffed 
with  waste  to  keep  the  grout  from  filling  them. 

In  regard  to  the  cost  of  walls  of  this  type,  Mr.  C.  H.  Cartlidge,  Bridge  En- 
gineer of  the  C.,  B.  &  Q.  R.  R.,  under  whose  supervision,  with  Mr.  L.  J.  Hotch- 
kiss,  Assistant  Bridge  Engineer,  the  walls  were  designed,  writes  as  follows:* 


FIG.  62.— FORMS  FORiRETAINING  WALL,  C.,  B.  &  Q.  R.  R. 

"This  wall  (reinforced  concrete)  will  show  an  economy  over  a  gravity 
wall  of  solid  concrete.  The  cost  of  a  large  amount  of  work,  including 
everything,  has  been  a  little  less  than  $9  per  yard.  For  the  concrete  only, 
exclusive  of  excavation  and  piling,  $6.23  per  yard.  Our  abutments  are 
solid  concrete  without  any  reinforcing.  These  cost  us  per  cubic  yard 
$5-55»  including  everything.  The  high  cost  per  yard  of  the  retaining 


*Bulletin  No.  108,  p.  426,  American  Railway  Engineering  and  Maintenance  of  Way 

arwMa+j/vn 

96 


Association. 


walls  for  excavation  and  piling  is,  of  course,  due  to  the  fact  that  com- 
paratively little  concrete  is  used  per  yard  of  excavation.  The  true  com- 
parison, therefore,  is  between  the  concrete  in  the  two,  being  for  the  retain- 
ing walls  as  stated  above,  $6.23  and  $5.03." 


FIG.  63.— REINFORCEMENT  IN  PLACE,  BUFFALO  RETAINING  WALL. 

REINFORCED  BUTTRESS  RETAINING  WALLS,  D*,  L.  &  W.  R.  R. 
The  photograph  in  Fig.  63  shows  the  method  of  constructing  and  reinforcing 
the  counterforts  of  the  retaining  wall  at  Buffalo,  New  York,  while  the  photo- 
graph in  Fig.  64  is  of  the  finished  wall. 

97 


In  addition  to  the  retaining  walls  just  described,  there  are  a  number  of 
illustrative  examples  of  different  types  of  walls  among  the  miscellaneous  pho- 
tographs at  the  end  of  this  book. 


FIG.  64.— BUFFALO  RETAINING  WALL,  D.,  L.  &  W.  R.  R. 


98 


CHAPTER  VII. 

STATIONS,  TRAIN  SHEDS  AND  PLATFORMS. 

Railroads  throughout  the  country  are  adopting  the  use  of  concrete  in  the 
construction  of  railway  stations  of  every  class,  in  many  cases  for  the  entire 
structure  and  in  others  for  integral  parts  such  as  foundations,  platforms,  smoke 
ducts,  stairways,  and  often  for  architectural  features,  such  as  cornices,  belt 


FIG.  65.— SCARSDALE  STATION,  N.  Y.  C.  &  H.  R.  R.  R. 

courses  and  platform  columns.  Its  permanence,  fire  resisting  qualities  and 
adaptability  to  architectural  treatment  renders  it  a  most  satisfactory  building 
and  structural  material  for  both  large  and  small  stations.  In  addition  to  the 
Marathon  Station,  the  O'Fallon  Station  and  the  Bush  Train  Shed,  a  number 
of  other  concrete  stations  are  shown  among  the  miscellaneous  photographs  at 
the  end  of  the  book. 

SCARSDALE  STATION,  N.  Y.  C.  &  H.  R.  R.  R.  The  photograph  in 
Fig.  65  shows  a  very  artistic  concrete  station  at  Scarsdale,  on  the  Harlem 
division  of  the  New  York  Central  and  Hudson  River  Railroad. 

99 


IOO 


MARATHON  STATION,  D.,  L.  &  W.  R.  R.  This  structure,  a  photo- 
graph of  the  track  side  of  which  is  shown  in  Fig.  66,  is  a  combination  passenger 
station  and  freight  house  of  simple,  yet  artistic  design  and  substantial  con- 
struction. 

With  the  exception  of  the  roof,  which  is  of  Ludowici  Celadon  tile  on 
wooden  rafters,  and  the  trusses  and  brackets,  the  building  is  of  concrete  con- 
struction throughout.  The  foundations  and  main  walls  are  of  plain  concrete, 
except  over  square  openings  where  reinforced  lintels  are  formed  by  placing 
three  %-inch  square  rods  near  the  soffit,  while  the  floors  and  platforms  are  of 
plain  concrete  laid  directly  on  a  cinder  base  and  surfaced  with  a  i^-inch  gran- 
olithic finish. 

The  walls  are  tool  finished  up  to  the  water-table,  and  above  that,  with  the 
exception  of  the  belt  course,  are  finished  by  floating  the  green  concrete  with 
water  and  rubbing  with  wire  brushes  immediately  after  removing  the  forms. 

All  the  concrete  was  mixed  in  the  proportions  of  i  part  Atlas  Portland 
Cement  to  2  parts  sand  and  4  parts  broken  stone. 

The  station  was  designed  by  Mr.  F.  J.  Nies,  architect  for  the  railroad,  under 
the  supervision  of  Mr.  Lincoln  Bush,  Chief  Engineer,  and  was  built  by  A.  E. 
Badgely,  general  contractor,  of  Binghamton,  N.  Y. 

O'FALLON  STATION,  WABASH  R.  R.  This  station,  a  photograph  of 
which  is  shown  in  Fig.  67,  is  typical  of  a  class  of  small  fireproof  stations  which 
the  Wabash  Railroad  are  erecting  to  take  the  place  of  the  ordinary  combusti- 
ble frame  building  formerly  used. 

They  are  built  in  three  sizes,  20  by  40  feet,  20  by  52  feet,  and  20  by  62  feet, 
and  consist  of  plastered  walls  with  floors,  platform,  foundations  and  chimney 
of  concrete.  These  stations  are  erected  at  about  the  cost  of  the  ordinary  frame 
building,  and  in  addition  to  being  fireproof  present  a  better  appearance  than 
the  former  type  of  structure. 

In  furring  for  the  outside  plastering  of  the  walls,  pieces  of  %-inch  diameter 
plain  round  rods  4  inches  long  are  fastened  to  the  studs  every  12  inches  and 
against  these  are  wired  ^2-inch  round  rods  placed  longitudinally  every  12 
inches.  To  these  horizontal  rods,  sheets  of  spiral  expanded  metal  lath,  No.  26 
gauge,  1 6  inches  wide  by  96  inches  long,  are  wired,  the  long  dimension  being 
placed  vertically.  After  this  is  plastered,  the  inside  of  the  building  is  furred 
in  a  similar  manner,  except  that  the  horizontal  rods  are  nailed  directly  to  the 
studding. 

The  plaster  for  the  first  coat  consists  of  a  mixture  of  three  cubic  feet  of 
well  slacked  lime  mortar  to  one  bag  of  Atlas  Portland  Cement.  This 
scratch  coat  is  applied  to  both  sides  of  the  expanded  metal  attached  to  the 
outer  side  of  the  studding  and  to  the  exposed  surface  of  the  expanded  metal  on 

101 


102 


the  inside.  When  this  coat  has  become  sufficiently  hard  both  sides  of  the 
outer  metal  lath  are  plastered  until  a  thickness  of  i*/2  inches  is  attained,  and 
the  inner  metal  lath  is  plastered  to  a  thickness  of  i  inch,  using  for  the  finishing 
coat  cement  mortar  in  proportions  one  bag  of  Atlas  Portland  Cement  to  2  cubic 
feet  of  sharp,  clean  sand. 

After  the  walls  are  dried  the  outside  surface  is  painted  with  two  coats  of 
waterproofing  compound  put  on  thick  enough  to  fill  in  and  hide  all  joints  and 
hair  cracks. 

In  the  new  depots  of  this  type  the  walls  up  to  the  window  sills  are  built 
of  solid  concrete,  which  greatly  improves  the  strength  and  general  appearance 
of  the  structure. 

These  stations  are  designed  by  and  built  under  the  supervision  of  the  Engi- 
neering Department  of  the  Wabash  Railroad,  Mr.  A.  O.  Cunningham,  Chief 
Engineer. 


FIG.:_68.— HOBOKEN  TERMINAL  TRAIN  SHED,  D.,  L.  &  W.  R.  R. 


TRAIN  SHEDS. 

HOBOKEN  TERMINAL  TRAIN  SHED,  D.,  L.  &  W.  R.  R.  The  train 
shed  for  the  new  Lackawanna  passenger  terminal  at  Hoboken,  N.  J.,  a  part 
section  of  which  is  shown  in  Fig.  69,  is  an  entirely  new  departure  from  the 

103 


hitherto  considered  standard  type  of  structure  for  this  purpose.  Instead  of 
comprising  a  series  of  high  arches,  which  in  the  common  type  of  train  shed  are 
continually  enveloped  in  a  haze  of  smoke  and  gases  from  the  locomotives,  it 
consists  essentially  of  a  system  of  low  arched  short  span  longitudinal  sections, 
just  high  enough  to  clear  the  largest  locomotive  in  use  on  the  line,  with  smoke 
ducts  of  reinforced  concrete  through  which  the  locomotive  gases  are  dis- 


Continuous  Skj///ght 

I  SlaqHoofinq 
Copper  Gutter  8m2l8  Deck  Bm.  ~ 


'to/ 


r  Concrete  fij&ftforcea 
with  J6gqge  3in.  Meistffxpanded  Metal 


/Reinforced  Cone  ret e\ 


Cinder  Filling 
•J —  6/76" 


JFt.6 

FIG.  69.-  PART  SECTION,  HOBOKEN  TRAIN  SHED,   D.,  L.  &  W.  R.  R. 

charged  directly  into  the  open  air.  As  will  be  seen  from  the  section  in  Fig. 
69  and  from  the  photograph  in  Fig.  68,  each  of  these  sections  cover  two  tracks 
and  the  sides  of  the  smoke  ducts  are  built  high  enough  to  prevent  driving  rain 
or  snow  from  reaching  the  platforms.  In  addition  to  the  smoke  ducts  the 
roof,  platforms  and  fence  footings  are  of  concrete  construction. 


104 


This  shed  was  designed  and  patented  by  Mr.  Lincoln  Bush,  Chief  Engineer 
of  the  Delaware,  Lackawanna  and  Western  Railroad,  and  erected  under  his 
supervision  by  the  company  forces  in  1907. 

The  same  type  of  train  shed  has  also  been  used  by  the  Lackawanna  Rail- 
road at  the  new  Scranton  station  and  by  the  Chicago  and  Northwestern  Rail 
way  Co.  at  its  new  terminal  in  Chicago. 


FIG.  70.— COHOES  STATION  AND  PLATFORM,  N.  Y.  C.  &  H.  R.  R.  R. 

PLATFORMS. 

While  plain  concrete  has  been  used  for  many  years  in  the  construction  of 
low  platforms  at  main  stations  the  adoption  of  high  platforms  on  rapid  transit 
and  suburban  lines  during  the  past  few  years  has  opened  up  a  new  field  for 
reinforced  concrete.  A  typical  ground  platform  is  shown  in  Fig.  71,  while 
two  types  of  high  platforms  of  reinforced  concrete  are  illustrated  and  de- 
scribed on  pages  106  to  in. 

STANDARD  CONCRETE  GROUND  PLATFORMS  AT  STATIONS, 
N.  Y.  C.  &  H.  R.  R.  R.  These  platforms,  a  typical  one  of  which  is  shown  in 
cross  section  and  plan  in  Fig.  71,  and  by  the  photograph  in  Fig.  70  are  usually 
constructed  200  feet  long  and  12  feet  wide  and  are  divided  into  blocks  of  not 
more  than  40  square  feet  area.  The  platform  illustrated  in  Fig.  71  is  for  only 


105 


one  passenger  track,  but  if  more  than  one  track  is  used  another  1 2-foot  plat- 
form is  provided  opposite  and  outside  of  the  additional  passenger  track  or 
tracks. 

The  concrete  is  mixed  in  the  proportions  of  i  part  Portland  cement  to  3 
parts  sand  to  6  parts  broken  stone  and  the  granolithic  finish  in  the  proportions 
of  i  part  cement  to  i^  parts  sand.* 


^Baggage  Cross/r?g       PLAN 


^6" Cinder 
'Screened 


FIG.  71.— STANDARD  GROUND  PLATFORM,  N.  Y.  C.  &  H.  R.  R.  R. 

STATION  PLATFORMS,  BROOKLYN  RAPID  TRANSIT  CO.  vThe 
platforms  on  either  side  of  the  tracks  are  about  240  feet  long  and  8  feet  wide 
and  are  constructed  of  a  reinforced  concrete  slab  carried  by  girders  of  the  same 
material  which  are  in  turn  supported  by  concrete  piers  placed  about  every  20 
feet.  The  photograph  in  Fig.  72  shows  the  track  side  of  one  of  the  platforms 
while  the  drawings  in  Fig.  73  show  the  essential  features  of  design  and  con- 
struction. 


*The  details  of  sidewalk  and  platform  construction   are   discussed  in   "Concrete  in 
Highway  Construction,"  published  by  the  Atlas  Portland  Cement  Company. 

106 


107 


•? 

^ 

\               / 
1             / 

c\ 

:> 

J 

I 

/ 

/  . 

L,,    urn-,-.." 

5SS-VWiVff  3  z.=-=*-^fff&*f*f  *£-£--F£t\* 

-|Hf~H- 

-.-. 

'    \  '  1 

i       \ 

!       \      l 

1 

<0 

1 

I 

5 

IS 

! 

*  § 

i 


, 


Trussed  Me  to/  La//7 


108 


Expansion  joints  are  provided  every  60  feet  by  separating  the  construction 
entirely  with  tarred  paper. 

The  outside  edges  of  the  platform  are  equipped  with  patent  bulb  nosing. 

The  fences  running  the  length  of  the  platform  and  forming  the  guard  rail- 
ings on  the  outside  and  ends  of  the  platforms  are  constructed  of  cement  pias- 
ter on  metal  lath  and  are  described  in  detail  in  Chapter  XVI. 

For  the  concrete  work  a  mixture  of  i  part  Atlas  Portland  Cement  to 
2  parts  sand  to  4  parts  3/^-inch  broken  stone  was  used  throughout.  The  i-inch 
granolithic  surface  of  the  platforms  was  mixed  in  the  proportions  of  i  part 
Atlas  cement  to  i  part  sand  and  i  part  pebble  grit  and  was  applied  simul- 
taneously with  the  last  course  of  concrete. 

In  designing  the  platforms,  a  live  load  of  150  pounds  per  square  foot  was 
assumed  and  the  concrete  was  figured  at  500  pounds  per  square  inch  extreme 
fiber  stress  while  the  steel  was  allowed  16,000  pounds  per  square  inch  in  ten- 
sion. 

The  platforms  were  designed  by  the  Engineering  Department  of  the 
Brooklyn  Rapid  Transit  System,  Mr.  W.  S.  Menden,  Chief  Engineer,  and 
were  constructed  under  his  supervision  by  Mr.  Thomas  G.  Carlin  of  Brooklyn, 
in  1907. 


I  ^    /Ouf///7e  of  /77//7//7?Lf/77  c/ear0/7ce. 

K-xT/S-  6-"-£-&-  -  /5ft.  -  O' 


$  CJ 

.^r---^-  C/rrders 


SECT/ON 

FIG.  74.— CROSS  SECTION  OF  STANDARD  ISLAND  PLATFORM.  N.  Y.  C.  &  H.  R.  R.  R. 

ELECTRIC  ZONE  STANDARD  PLATFORMS,  N.  Y.  C.  &  H.  R.  R.  R. 

One  of  the  most  important  features  of  the  Electric  Zone  improvement  work 
of  the  New  York  Central  and  Hudson  River  Railroad  is  the  adoption  of  high 
platforms  on  the  suburban  side  of  all  local  stations  within  the  Zone.  This  not 
only  enables  greater  ease  in  the  interchange  to  and  from  trains,  but  greatly 
increases  the  rapidity  of  the  service. 


109 


As  will  be  seen  from  the  cross-sections  in  Figs.  74  and  75,  which  show  the 
details  of  construction  of  an  island  and  outside  platform,  the  type  adopted 
comprises  two  longitudinal  reinforced  8-inch  walls  with  a  6-inch  reinforced 
deck  or  floor  plate  spanning  the  walls  and  overhanging  2  feet  6  inches  on 
either  side.  The  width  varies  from  12  to  15  feet,  while  the  height  is  deter- 
mined by  the  elevation  of  the  rails  according  to  the  degree  of  curve,  which  is 
four  feet  above  the  rails  on  tangents  and  curves  up  to  three  degrees  and  thirty 
minutes. 

In  plan  the  arrangement  of  the  platform  varies  greatly  according  to  the 
location.  The  suburban  stations  have  high  platforms  about  350  feet  long,  on 

Ou/-//f?e   of 

\ 


*  Bars  6cc-       ^c/ncfer 

77 /e  Dro/f? 
SECT/OA/ 

FIG.  75.— CROSS  SECTION  OF  STANDARD  OUTSIDE  PLATFORM,  N.  Y.  C.  &  H.  R.  R.  R. 

either  side,  outside  of  the  group  of  four  tracks,  and  the  combination  stations 
have  two  high  outside  platforms  and  a  middle  low  platform  between  the  ex- 
press tracks  on  both  sides,  with  a  high  platform  at  one  end  for  a  distance  of 
350  feet  and  a  low  one  of  the  same  length  adjoining  it. 

All  stations  are  provided  with  overhead  bridges  or  subways  connecting 
with  the  various  platforms. 

The  concrete  is  of  1 13 :6  proportions,  with  exposed  surfaces  faced  with 
^2-inch  cement  finish  mixed  in  the  proportions  of  i  cement  to  1^2  sand.  All 
exposed  edges  are  rounded  to  a  i-inch  radius. 

The  platforms  are  divided  into  blocks  of  not  more  than  40  square  feet  area 
and  expansion  joints  are  to  be  provided  every  25  to  40  feet. 

These  platforms  are  designed  by  the  engineering  force  of  the  N.  Y.  C.  &  H. 
R.  R.  R.  under  the  supervision  of  Mr.  George  A.  Harwood,  Chief  Engineer  of 
Electric  Zone  Improvements. 

no 


CHAPTER  VIII. 

COAL  AND  SAND  STATIONS  AND  ASH  HANDLING  PLANTS. 

Reinforced  concrete  is  peculiarly  adapted  to  the  construction  of  structures 
which  are  to  be  used  for  the  storage  of  coal  on  account  of  its  undoubtable  fire- 
resisting  qualities,  permanence  and  strength. 


FIG.  76.— COAL  AND  SAND  STATION,  N.  &  W.  RY. 

Through  the  use  of  inferior  bins  such  as  have  been  constructed  of  timber 
or  steel,  the  railroads  of  this  country  have  suffered  much  inconvenience  and 
heavy  expense.  The  spontaneous  combustion  to  which  coal  is  subject  when 
stored  in  great  quantities  not  only  results  in  the  loss  of  the  coal  itse'.f  and  the 
damaging  of  much  valuable  machinery,  but  also  in  the  destruction  of  the  bin, 
if  it  is  constructed  of  either  wood  or  steel. 

This  condition  has  led  to  entirely  reinforced  concrete  structures,  even 
though  the  initial  cost  is  higher  than  for  wood  or  steel.  The  coal  and  sand 
stations  which  have  thus  far  been  constructed  of  reinforced  concrete  have 
given  entire  satisfaction. 


in 


CONCORD  COAL  AND  SAND  STATION,  N.  &  W.  RY.  This  com- 
bination coaling  and  sand  station,  shown  by  the  photograph  in  Fig.  76,  was 
built  and  entirely  equipped  for  the  Norfolk  and  Western  Railway  by  the  Link 
Belt  Co.  of  Philadelphia  during  the  summer  of  1907.  The  reinforced  concrete 


E/evotor  Boot hSfe 


Rec/procot/ng    Feeder- 


FIG.    77.— CROSS-SECTION     SHOWING     MECHANICAL     EQUIPMENT     OF    CONCORD    COAL    AND     SAND 

STATION. 

details  were  designed  and  worked  out  by  Mr.  Walter  Loring  Webb,  Consult- 
ing Engineer,  of  Philadelphia,  and  the  concrete  work  was  sublet  to  McLaugh- 
lin  Brothers,  of  Baltimore,  Md. 

In  general  the  station  consists  of  an  elevated  coal  pocket  having  a  capac- 
ity of  260  tons  of  coal,  and  a  wet  sand  storage  house  on  the  ground  with  an. 
elevated  dry  sand  bin.  From  a  study  of  the  drawing  in  Fig.  77,  showing  the 
mechanical  equipment  of  the  plant,  it  will  be  seen  that  the  coal  is  brought  to 

112 


113 


the  pocket  on  a  side  track,  and  dumped  through  a  10  by  12  foot  track  hopper 
into  a  reciprocating  feeder  which  delivers  it  into  a  steel  bucket  elevator  dis- 
charging into  a  conveyor  trough  above  for  distribution  into  the  pocket.  The 
photograph  in  Fig.  79  shows  the  conveyors  and  the  conveyor  trough  over  the 
pocket.  The  coal  is  fed  to  the  engine  tenders  through  hinged  gates  and  over 
counterweighted  coaling  chutes,  two  directly  under  the  pocket  and  two  over 
the  track  in  front  of  the  pocket.  The  wet  sand  passes  into  a  dryer  emptying 
into  a  sand  pit  underneath,  where  it  is  scooped  up  and  carried  by  a  sand  ele- 
vator which  dumps  it  from  above  into  the  dry  sand  bin.  From  this  bin  it  is 
fed  to  the  engines  through  two  telescopic  sand  spouts. 


FIG.  79.— CONVEYORS  OVER  COAL  POCKET,  CONCORD  COALING  AND  SAND  STATION. 

In  designing  the  structural  features  of  the  station,  the  unit  compression 
in  the  concrete  was  taken  as  500  pounds  per  square  inch,  and  the  tension  in  the 
steel  as  16,000  pounds  per  square  inch.  The  side  walls  were  designed  on  the 
basis  of  the  computed  lateral  pressure  exerted  by  bituminous  coal  weighing 
47  pounds  per  cubic  foot.  This  gave  a  maximum  lateral  pressure  of  248 
pounds  at  the  bottom  of  the  pocket,  and  a  vertical  pressure  on  the  bottom 
slab  of  nearly  1,000  pounds  per  square  foot.  The  essential  features  of  design 
and  construction  are  shown  very  clearly  by  the  longitudinal  and  transverse 
sections  in  Fig.  78. 

114 


In  the  construction  of  the  building,  concrete  mixed  in  the  proportion  of  I 
part  Atlas  Portland  Cement  to  2  parts  sand  to  4  parts  broken  stone,  was 
used  throughout  and  was  mixed  in  a  cube  mixer  equipped  with  hoisting  en- 
gine and  elevator  and  delivered  over  the  work  in  batch  carriers.  The  cost  of 
the  concrete  work  was  $8,600. 


FIG.  80.     MURRAY  HILL  RETAIL  COAL  POCKET,  D.,  L.  &  W.  R.  R. 

ASH  HANDLING  PLANTS. 

Inasmuch  as  wood  burns  and  steel  corrodes,  it  has  long  been  a  problem 
as  to  how  to  build  ash  handling  plants  capable  of  withstanding  the  destructive 
effect  of  ashes  quenched  with  water.  The  advent  of  reinforced  concrete  into 
the  field  of  railroad  construction  has  successfully  solved  this  problem.  At  the 
present  time  most  of  the  plants  being  built  throughout  the  country  consist  of 
a  steel  framework  which  support  bins  constructed  of  reinforced  concrete. 
The  accompanying  photograph  in  Fig.  82  is  a  good  example  of  such  a  plant 
designed  and  erected  in  1905  by  the  Link  Belt  Company  for  the  Norfolk  & 
Western  Railway  at  Bluefield,  W.  Va. 

The  ash  bin  has  a  storage  capacity  of  30  tons.  Ashes  are  dumped  from  the 
engine  into  i-ton  tubes  which  rest  on  trucks  in  the  dump  pit  below,  with  their 
tops  flush  with  the  rails,  and  are  raised,  dumped  into  the  bin  and  returned  auto- 
matically by  an  electric  hoist.  In  the  photograph  one  of  the  skips  is  seen  in 
action,  while  on  the  drawing  in  Fig.  81  is  shown  a  cross  section  of  the  dump 

"5 


116 


pit.     The  ashes  are  emptied  from  the  bin  through  a  discharge  gate  into  cars 
on  a  track  directly  beneath. 

The  details  of  construction  of  the  concrete  work  of  the  bin  are  shown  in 
Fig.  8 1  together  with  the  forms  and  the  manner  in  which  they  were  supported 
by  the  steel  framework  of  the  building.  The  cost  of  the  concrete  work  includ- 
ing the  forms  was  about  $700. 


FIG.  82.— ASH  HANDLING  PLANT,  BLUEFIELD,  W.  VA.,  N.  &  W.  RY. 

HOBOKEN  COAL  TRESTLE,  D.,  L.  &  W.  R.  R.  As  shown  by  the 
photograph  in  Fig.  83,  this  trestle  forms  an  approach  by  which  loaded  coal 
cars  may  be  taken  to  the  level  of  the  second  floor  of  the  power  house  where 
the  coal  is  dumped  to  the  space  in  front  of  the  boilers.  It  will  be  seen  that  the 
trestle  proper,  which  is  226  feet  3  inches  long,  comprising  18  bents  on  piers 
spaced  12  feet  on  centers,  has  for  an  inner  abutment  the  wall  of  the  power 
house  and  for  the  outer  abutment  the  end  of  an  approach  112  feet  4  inches  long. 

From  out  to  out  the  trestle  is  16  feet  wide,  about  one-half  this  width  being 
taken  up  by  a  walk  each  side  of  the  track. 

The  footings,  which  rest  on  piles,  are  4  feet  9  inches  wide  and  3  feet  thick. 

Each  pier  is  19  feet  wide  and  18  inches  thick  at  the  top  with  a  batter  of  i 
inch  per  foot  in  cross  section  of  the  trestle  and  */£  inch  per  foot  in  longitudinal 

117 


section,  and  is  reinforced  vertically  with  34-inch  square  bars  placed  in  two 
rows  3  inches  from  the  outside  of  the  pier,  5  inches  on  centers  underneath  the 
stringers,  and  9  inches  on  centers  between  the  stringers.  In  addition  to  these 
vertical  bars,  similar  ones  are  placed  horizontally  18  inches  apart. 

The  beams  or  stringers  resting  on  these  piers  are  18  inches  by  27  inches,  and 
are  reinforced  with  three  i^-inch  square  bars,  two  being  bent  up  at  the  quar- 
ter points  to  take  care  of  the  diagonal  tension.  Over  each  pier  the  top  of  the 
stringer  is  also  reinforced  with  four  i  ^2-inch  square  bars  8  feet  4  inches  long. 
Every  two  feet,  3^-inch  bolts  12  inches  long  are  embedded  9^  inches  in  the 
top  of  the  stringer  to  which  are  secured  clamps  for  holding  the  rails  in  place. 


FIG.  83.— COAL  TRESTLE,  HOBOKEN,  N.  J.,  D.,  L.  &  W.  R.  R. 

As  will  be  seen  from  the  photograph  in  Fig.  84,  the  sidewalks  are  carried  by 
an  inverted  rail  at  each  bent  which  extends  the  width  of  the  trestle.  To  these 
rails  clips  are  attached  every  6  inches  with  openings  in  each  leg  through  which 
the  rods  forming  the  reinforcement  of  the  sidewalk  are  passed. 

A  mixture  of  i  :2  14  was  used  throughout. 

The  trestle  was  designed  and  constructed  by  the  Engineering  Department 
of  the  Delaware,  Lackawanna  and  Western  Railroad  in  1907  under  the  super- 
vision of  Mr.  Lincoln  Bush,  Chief  Engineer,  and  Mr.  George  T.  Hand,  Assist- 
ant Engineer,  with  Mr.  E.  I.  Cantine  as  Division  Engineer. 

118 


FIG.  84.— HOBOKEN  COAL  TRESTLE  UNDER  CONSTRUCTION,  D.,  L.  &  W.  R.  R. 


_v 

FIG.  85.— REINFORCED  CONCRETE  CINDER  PIT,  PITTSBURG  SHOPS  OF  KANSAS  CITY  SOUTHERN  RY. 

Built  by  Arnold    &    Co.,  of  Chicago. 

IIQ 


120 


CHAPTER  IX. 


ROUNDHOUSES  AND  TURNTABLE  PITS. 

ROUNDHOUSES. 

The  adaptability  of  concrete  to  roundhouse  construction  is  clearly  demon- 
strated in  the  report*  submitted  on  that  subject  by  the  Committee  on  Build- 
ings of  the  American  Railway  Engineering  and  Maintenance  of  Way  Associa- 
tion before  the  annual  convention  of  that  society  held  in  Chicago,  March,  1908. 

For  the  purpose  of  discussion,  the  roundhouse  was  considered  divided  into 
Foundations  and  Pits,  Roof,  Supporting  Columns  and  Outer  Walls;  and  ex- 
cerpts from  the  report  are  given  below  in  the  order  named. 

FOUNDATIONS  AND  PITS.  "While  in  some  cases  local  conditions  may 
favor  the  use  of  stone  or  brick  for  foundations  and  pits,  it  may  be  stated,  as  a 
general  proposition,  that  good  practice  in  roundhouse  construction  now  re- 
quires the  use  of  concrete  for  these  parts  of  the  structure.  When  a  solid 
foundation  cannot  be  obtained  within  a  few  feet  below  the  floor  level  of  the 
building  a  considerable  saving  may  be  effected  by  the  use  of  reinforcement." 

ROOF.  "In  economy  of  first  cost,  durability  and  fire-resisting  qualities, 
there  is  no  other  fireproof  roof  construction  which  is  equal  to  reinforced  con- 
crete. Steel  except  as  a  reinforcement  for  concrete  is  not  a  satisfactory  ma- 
terial for  engine  house  roof  construction." 

SUPPORTING  COLUMNS.  "If  the  roof  is  of  reinforced  concrete,  it 
should  be  supported  by  columns  of  the  same  material  in  the  outer  and  end 
walls,  as  well  as  in  the  interior  of  the  building.  These  columns  should  be' 
concreted  with  the  roof,  the  concrete  being  run  into  the  forms  from  above. 
The  columns  on  the  inner  circle  to  which  the  doors  are  attached  should  be 
of  some  other  material  than  concrete,  preferably  steel  or  cast  iron." 

OUTER  WALLS.  "For  a  structure  roofed  with  reinforced  concrete,  the 
curtain  walls  may  be  of  brick,  plain  concrete,  reinforced  concrete  or  plaster. 
Concrete  will,  if  properly  made,  give  good  service  and  local  costs  of  materials 
and  labor  would  ordinarily  determine  which  of  the  first  three  styles  of  curtain 
walls  named  above  should  be  built.  The  plaster  curtain  wall  may  be  used 
where  it  is  desirable  or  necessary  to  reduce  the  first  cost  to  a  minimum. 

"To  build  such  a  wall  Portland  cement  is  mixed  with  enough  lime  so  that 
it  can  be  worked  with  a  trowel  and  is  plastered  on  expanded  metal.  The  lat- 


*Proceedings  of  the  Ninth  Annual  Convention,  Vol.  9,  p.  166. 

121 


|H- 


19 


ae'lS 


« 


f  s  . 

«o 

3  §3 


• 


0' 

II 


« 


B- 


•83 


"83 

O    03 

ow 


3-89 


H 

00® 


Ss 
18 


I®  III® 
lls 


II 

CO® 


*M    "4  **M  ~"  «M  "  *^  "  T3  *O 

GO  ao  co  aud  o 

•S»  -s»  -S3»  IM  o  o 

«  «  «  «  ^  £ 

COMPARISON  OF  COST  OF  DIFFERENT  TYPES  OF  ROUNDHOUSES. 

122 


\-U9Z- 


4! 
If 


I! 


Is 
11 
II 


=* 

is 


• 

.a  to  bfl-^ 


w«  §« 


~  s  »  i  s 

sjjjj 

J*5il 


a 

0.-0 


I    « 

888" 
&M 


;   ;  a   • 
.'   :  c"* 

isP 
JU 


ter  is  stiffened  with  rods  and  channel  irons,  which  are  used  to  support  the 
window  frames.  A  wall  of  this  character  can  be  built  more  quickly  than  a 
concrete  wall,  is  efficient  and  should  be  durable.  If  damaged  by  a  locomo- 
tive or  otherwise,  it  is  easily  repaired,  and  alterations  can  be  readily  made. 
Used  with  concrete  columns,  it  should  not  crack,  and  its  first  cost  is  but  about 
half  that  of  a  brick  wall." 

COST.  "The  cost  of  concrete  construction  in  roundhouses  depends  largely, 
upon  the  number  of  times  the  forms  can  be  used.  It  follows,  therefore,  that 
where  the  structure  is  large  and  the  forms  for  each  unit  or  stall  can  be  used 
many  times  in  the  same  roundhouse,  the  cost  per  stall  is  much  less  than  in  a 
small  building.  Consequently  reinforced  concrete  construction  is  more 
economical  in  large  than  in  small  roundhouses,  when  compared  with  brick  or 
frame  construction." 

The  costs  of  the  different  types  of  construction  are  compared  in  the  table5" 
on  page  122. 

This  table  gives  in  detail  a  comparative  statement  of  the  cost  and  annual 
charges  per  stall  of  six  types  of  roundhouses,  the  first  three  being  roofed 
with  reinforced  concrete  and  having  outer  walls  of  concrete,  brick  and  plaster, 
respectively,  in  the  order  named.  The  fourth  given  is  the  same  type  as  the 
third  and  merely  shows  the  increase  in  unit  cost  for  the  reinforced  type  when 
the  building  is  reduced  in  size. 

With  these  figures  as  a  basis  it  is  evident  that  the  concrete  house  is  in  the 
long  run  more  economical,  because  of  its  greater  permanency  and  the  lesser 
chance  of  damage  to  it  and  the  equipment  it  contains,  by  fire  and  other  causes. 

In  addition  to  the  roundhouse  described  below  a  number  of  different  types 
of  concrete  roundhouses  are  illustrated  by  the  photographs  in  the  back  of  the 
book. 

WATERBURY  ROUNDHOUSE,  N.  Y.,  N.  H.  &  H.  R.  R.  While  this 
roundhouse  as  designed  includes  22  stalls,  the  part  constructed  at  the  present 
time  consists  of  10  stalls,  each  comprising  about  8  degrees  of  the  circle,  and  is 
connected  at  one  end  to  a  machine  shop. 

As  will  be  seen  from  the  radial  section  in  Fig.  89  the  house  consists  of  four 
circumferential  rows  of  hooped  concrete  columns  carrying  beams  and  roof 
slabs  of  reinforced  concrete. 

The  entrance,  as  shown  by  the  stall  elevation  in  Fig.  87,  is  closed  in  by 
large  round  slat  rolling  doors  between  the  columns,  while  the  outer  circle  is 
encompassed  by  a  brick  wall  with  large  glass  windows  with  concrete  sills 
directly  in  line  with  the  tracks. 


*Proceedings   American   Railway  Engineering  and   Maintenance   of  Way  Associa- 
tion, Vol.  9,  p.  182. 

123 


124 


Sx/Q 


Each  stall  is  equipped  with  an  asbestos  lumber  smoke-jack  and  each  pit  is 
provided  with  steam  pipes  for  removing  ice  and  snow  from  the  locomotives. 
Fig.  88,  which  is  a  cross  section  of  a  stall  pit,  shows  the  arrangement  of  these 
pipes. 

Permanent  compressed  air  jacks  are  installed  in  drop  pit  under  the  tracks 
of  two  of  the  longitudinal  pits  to  remove  trucks  which  can  then  be  slid  into  a 
transverse  pit  and  thence  into  the  machine  shop. 


2.Ft.6"At  outer  circle. 


i 
3 

| 

s 

5! 

*x 

M* 


$31 


3  :*>••<>'•>: 
*<fl/D  •»'£•:* 

itife 

&•£*&&?%& 


-3ftO" 


FIG.  88.—CROSS  SECTION  STALL  PIT,  WATERBURY  ROUNDHOUSE. 

The  drawings  in  Fig.  89  show  the  essential  details  of  design  and  construc- 
tion of  the  columns  and  roof  construction. 

The  columns  are  of  square  section  14  by  14  inches  and  are  reinforced  with 
six  5^-inch  plain  square  bars  hooped  with  s/£-inch  round  hooping  y2-inch  pitch. 

The  method  employed  in  constructing  the  roof  presents  a  rather  unique 
and  interesting  feature.  While  the  main  girders  were  cast  in  place  in  the 
usual  manner  the  intermediate  beams  and  roof  slabs  were  moulded  on  the 
ground,  cured  and  hoisted  to  their  required  position  and  grouted  in  place. 
The  intermediate  beams,  set  in  reinforced  bracketed  pockets  on  the  main  girder 
to  which  they  are  rigidly  connected,  were  locked  by  extending  the  reinforce- 
ment from  both  beam  and  packet  and  filling  the  joints  with  wet  concrete.  The 
photograph  in  Fig.  87  of  the  roundhouse  during  erection,  shows  this  form  of 
construction  very  clearly. 

As  will  be  seen  from  Fig.  89  the  slabs  which  are  made  in  widths  of  about 
four  feet  rest  directly  on  top  of  the  intermediate  beams  and  main  girders. 


125 


These  slabs  are  3  inches  thick  and  are  reinforced  with  woven  wire  mesh  fabric. 

After  the  slabs  were  set,  the  roof  was  covered  with  pitch  and  slag. 

A  mixture  of  1 12  14  concrete  was  used  throughout  in  the  construction  of 
the  roundhouse. 

He/nforced      Concrete,     ffoof 
rt-       Covered     with      <s/a_a     roofing 


Heating  Duct      Engine      Pit 


Reinforced     Concrete      Columns 
RA1D/AL         SECTION 

•^..n.-i^-.  ^_.  Xa/7/7 

50 1x3 in.  Kahn  Bar 

<§ 


LLLVATION 


SECT/ON  ONAA      SECTION  ONB^ 


PAFiT 


FIG.  89.—  RADIAL  SECTION  WITH  DETAILS  OF   ROOF  CONSTRUCTION,  WATERBURY  ROUNDHOUSE. 

The  roundhouse  was  designed  by  the  engineering  department  of  the  New 
York,  New  Haven  and  Hartford  Railroad,  Mr.  Edwin  Gagel,  Chief  Engineer, 
under  the  direction  of  Mr.  E.  H.  McHenry,  Vice-President,  and  was  built  in 
1909  by  the  O'Brien  Construction  Company  of  Waterbury. 

HURON  ROUNDHOUSE,  C.  &  N.  W.  RY.  The  photograph  in  Fig.  90 
shows  the  4O-stall  engine  house  of  the  Chicago  and  Northwestern  Railway  at 
Huron,  S.  D.,  under  construction.  This  is  a  combination  brick  and  concrete 


126 


structure  with  all  of  the  foundations,  pits  and  underground  work  of  concrete 
construction.  It  was  built  for  the  Chicago  and  Northwestern  Railway  by 
the  Charles  W.  Gindele  Co.  of  Chicago  in  1907. 


FIG.  90.— HURON  ROUNDHOUSE  DURING  CONSTRUCTION. 


TURNTABLE  PITS. 

In  connection  with  roundhouse  construction  the  subject  of  turntable  pits  is 
of  special  interest.  The  facility  and  cheapness  with  which  concrete  pits  can 
be  built  is  so  generally  recognized  that  practically  all  turntable  pits  con- 
structed to-day  are  built  of  concrete. 

The  photograph  in  Fig.  86,  page  120,  is  of  a  standard  turntable  pit  on  the 
Santa  Fe  System,  while  the  drawings  in  Fig.  91  show  the  standard  pit  for  a  30- 
foot  turntable  on  the  N.  Y.  C.  &  H.  R.  R.  R. 

STANDARD  PIT,  N.  Y.  C.  &  H.  R.  R.  R.  Fig.  91  shows  the  essential 
details  of  design  and  construction  of  this  pit,  together  with  a  drawing  of  the 
turntable  itself. 

As  will  be  seen  from  the  drawings  in  Fig.  91,  the  turntable  is  supported  by 
a  center  pier  surmounted  by  a  complete  templet  5  feet  by  5  feet  by  i  foot  6 
inches.  The  concrete  for  the  pier  itself  is  mixed  in  the  proportion  of  i  part 

127 


Portland  cement  to  3  parts  sand  to  6  parts  broken  stone  and  the  templet  or  cap 
in  the  proportions  of  i  :i  12. 

The  floor  of  the  pit  consists  of  4  inches  of  1 12  14  concrete  laid  on  8  inchas 
of  well  tamped  cinders. 


4-in  Concrete 


SECTION  AT  CENTRE 
PART  PLAN' 

FIG.  91.— STANDARD  80-FT.  TURNTABLE  PIT,  N.  Y.  C.  &  H.  R.  R.  R. 

The  circular  run  rail  is  carried  on  a  seat  of  1 13 :6  concrete  resting  on  a 
foundation  5  feet  wide  and  4  feet  high  composed  of  1 14:7^/2  concrete. 

All  exposed  corners  and  edges  of  the  concrete  work  are  rounded  to  a  i-inch 
radius. 


CHAPTER  X. 

SIGNAL    TOWERS,    WATER    TANK    SUPPORTS    AND    BUMPING 

POSTS. 


SIGNAL  TOWERS. 

Railroads  throughout  the  country  are  experiencing  a  period  of  architect- 
ural Renaissance.  Structures  which  have  in  the  past  been  built  of  tempo- 
rary construction,  apparently  regardless  of  outward  appearance,  are  being  re- 
placed by  permanent  buildings  of  artistic  design.  This  is  particularly  true  in 
the  case  of  signal  towers,  the  old  unsightly  and  necessarily  temporary  wooden 
structures  being  superseded  either  by  entire  concrete  or  combination  concrete 
and  brick  towers  of  pleasing  appearance  and  permanent  construction. 


FIG.  93.- SIGNAL  TOWER,  NAUGATUCK,  CONN.,  N.  Y.,  N.    H.  &  H.  R.  R. 

NAUGATUCK  JUNCTION  TOWER,  N.  Y.,  N.  H.  &  H.  R.  R.  With  the 
exception  of  the  roof,  which  is  of  Ludowici  Celadon  tile  on  wooden  rafters,  this 
tower  is  of  concrete  construction  throughout.  The  foundation  and  both  ex- 

129 


130 


terior  and  interior  walls  are  of  plain  1 13 15  gravel  concrete,  while  the  floors  are 
of  i  :2 14  gravel  concrete  reinforced  with  No.  16  2%-inch  expanded  metal.  The 
general  features  of  design  and  construction  are  shown  very  clearly  by  thd 
drawings  in  Fig.  94. 

As  will  be  seen  from  the  photograph  in  Fig.  93,  the  architectural  treatment 
of  the  building  is  enhanced  by  the  use  of  indented  arches  over  the  lower  win- 
dows, and  by  a  projecting  ornamented  belt  course  which  runs  around  the 
entire  building  and  serves  as  a  lintel  for  the  upper  windows.  The  roof  is  de- 
signed along  pagoda  lines  with  a  very  pleasing  result. 

The  tower  was  designed  by  the  engineering  department  of  the  railroad 
and  built  by  its  building  department  in  1906. 


FIG.  95.— KINGSBRIDGE  SIGNAL  TOWER,    N.  Y.  C.  &  H.  R.  R.  R. 


KINGSBRIDGE  TOWER,  N.  Y.  C.  &  H.  R.  R.  R.  The  standard  signal 
towers  of  the  electric  zone  of  the  New  York  Central  and  Hudson  River  Rail- 
road are  combination  brick  and  concrete  structures,  a  typical  example  of 
which  is  shown  by  the  photograph  of  the  Kingsbridge  Tower  in  Fig.  95.  The 
footings  and  foundation  walls  below  grade  are  of  1 14 :j%  concrete,  and  the 
walls  above  grade  up  to  the  first  floor  level  are  of  1 13  :6  concrete.  All  the  sills 
and  lintels,  the  coping,  the  overhanging  bay  window  and  supporting  brackets 

131 


and  the  cornice  are  of  1 12  14  concrete,  the  details  of  construction  of  which  are 
shown  by  the  drawings  in  Fig.  96. 


Water- proof  cement 
wash  Jin.  thick 


Standard  Pitch  &  Slag  Hoofing 

3?£!SS5i 


I2.in. 


£-8intd*I  Beams 


/,-/-«--,        "         £** STORY  W/NDOW 
Concrete\  Bracket 

Cement  Mou/d 
SLC.  THROUGH    BAY  WINDOW 

FIG.  96.— DETAILS  OF  CONSTRUCTION,  KINGSBRIDGE  SIGNAL  TOWER,  N.  Y.  C.  &  H.  R.  R.  R. 

The  excellent  finish  of  this  work  was  obtained  by  floating  the  green  con- 
crete with  water  and  rubbing  it  with  a  mortar  brick  composed  of  i  part  cement 
to  2  parts  sand.  The  floor  and  roof  construction  consists  of  1 12  14  concrete 
slabs,  reinforced  with  ^-inch  round  rods,  supported  by  steel  I-beams. 

GROVE  ST.  SIGNAL  TOWER,  D.,  L.  &  W.  R.  R.  This  tower,  located 
about  250  feet  west  of  Grove  Street,  Hoboken,  is  built  entirely  of  reinforced 


132 


'oncrete   Bracket 


133 


concrete  and  was  designed  and  constructed  by  the  engineering  department 
of  the  Delaware,  Lackawanna  and  Western  Railroad,  Mr.  Lincoln  Bush,  Chief 
Engineer,  and  Mr.  F.  J.  Nies,  architect.  The  general  details  and  essential 
features  of  design  and  construction  are  shown  in  Fig.  97,  while  the  photograph 
in  Fig.  98  is  of  the  finished  structure. 


FIG.  98.— SIGNAL  TOWER,  GROVE  STREET,  HOBOKEN,  D.,  L.  &  W.  R.  R. 

There  are  several  interesting  features  of  construction  in  connection  with 
the  tower  which  are  somewhat  out  of  the  ordinary.  The  side  walls  rest  on 
creosoted  piles  spaced  2  feet  8  inches  apart,  while  the  front  and  rear  walls  are 
carried  by  reinforced  concrete  girders  spanning  from  side  wall  to  side  wall. 
At  the  first  floor  level  there  is  a  concrete  platform  leading  to  the  iron  sfairs 
in  the  rear  which  is  supported  on  reinforced  concrete  brackets  cantilevering  3 
feet  from  the  side  wall  of  the  building.  The  roof,  which  overhangs  i  foot  10 
inches,  and  appears  from  the  ground  to  be  flat,  is  a  reinforced  concrete  slab 
pitching  from  a  thickness  of  3  inches  at  the  walls  to  10  inches  at  the  center. 
With  the  exception  of  the  overhang,  which  is  flashed  with  i6-ounce  copper, 
the  concrete  slab  is  covered  with  slag  roofing. 

The  concrete  for  the  entire  building  was  mixed  in  the  proportions  of  1 12 14, 
and  all  exposed  surfaces  were  rubbed. 

In  designing  the  tower  a  ratio  of  elasticity  of  15  was  assumed,  and  the  con- 


crete  was  figured  at  600  pounds  per  square  inch  fiber  stress,  500  pounds  per 
square  inch  direct  compression,  and  50  pounds  per  square  inch  shear,  while  the 
steel  was  given  a  tensile  stress  of  16,000  pounds  per  square  inch. 

WATER  TANK  SUPPORTS. 

Owing  to  its  strength,  rigidity  and  resistance  to  fire  and  decay,  reinforced 
concrete  is  aptly  suited  for  the  construction  of  water  tank  supports. 

In  addition  to  the  support  described  below,  other  examples  of  this  form  of 
construction  are  illustrated  among  the  miscellaneous  photographs  in  the  back 
of  the  book. 


Bars 
Bars 


FIG.  99.— DETAILS  OF  CONSTRUCTION,  WATERBURY  WATER  TANK  SUPPORT. 

WATER  TANK  SUPPORT  AT  WATERBURY,  N.  Y.,  N.  H.  &  H.  R.  R. 
This  tank  support,  octagonal  in  form,  is  30  feet  9  inches  wide,  with  the  plat- 
form carrying  the  water  tank  40  feet  above  the  ground  line.  It  is  designed  to 
carry  a  55,400  gallon  wooden  tank. 


The  essential  details  of  design  and  construction  are  shown  clearly  by  the 
drawings  in  Figs.  99  and  100,  while  the  photograph  in  Fig.  101  is  of  the  finished 
support. 


0*  kj 

cvj      TOP  PLAN 


i  in.  i 


FOUNDATION    PLAN 


ELEVATION 

AND 

HALF 


FIG.  100.— PLAN,  HALF  SECTION  AND  HALF  ELEVATION,  WATER  TANK  SUPPORT,  N.  Y.,  N.  H.  &  H.  R.  R. 

The  method  of  reinforcing  the  supporting  columns  presents  a  rather  unique 
and  interesting  feature.  This  reinforcement  consists  of  two  95-pound  third 
rails  placed  back  to  back  and  riveted  every  3  feet,  making  a  section  in  the  form 
of  a  star  strut. 

The  platform  which  is  9  inches  thick  is  reinforced  with  %-inch  corrugated 
bars  4  inches  on  centers  in  both  directions  while  the  beams  and  diagonal 
braces  are  reinforced  with  %-inch  corrugated  bars  bent  and  hooked  as  shown 
in  Fig.  99. 


FIG.  101.— WATER  TANK  SUPPORT,  WATERBURY,  CONF.,  F.  Y.,  F.  F.  &  H.  R.  R. 

137 


Concrete  for  the  support  was  mixed  in  the  proportions  of  i  part  Portland 
Cement  to  2 /parts  sand  and  to  4  parts  screened  gravel. 

The  structure  was  designed  by  the  Engineering  Department  of  the  railroad 
and  built  by  the  O'Brien  Construction  Company  of  Waterbury,  Conn.,  during 
the  fall  of  1908. 


FIG.  102.— CONCRETE  BUMPING  POSTS,  D.,  L.  &  W.  R.  R. 


BUMPING  POSTS. 

A  bumping  post,  to  insure  safety  against  rotating  or  breaking  down  under 
constant  buffing,  must  be  constructed  so  as  to  be  anchored  in  the  earth  direct 
ratherthan  attached  to  the  track  itself,  as  is  the  case  with  practically  all  of  the 
patented  posts  now  in  use  on  railways  in  this  country.  By  the  use  of  concrete, 
bumping  posts  can  be  constructed  economically  so  as  to  meet  the  conditions 
of  stability  and  permanence. 

fe  *:/•$*'*- 

STANDARD  CONCRETE  BUMPING  POSTS,  D.,  L.  &  W.  R.  Ik  This 
post  is  given  in  detail  by  the  drawings  in  Fig.  103,  while  the  photograph  in  Fig. 
102  shows  three  of  the  posts  in  service  at  Newark,  N.  J.  As  will  be  seen  from 
the  drawings,  the  buffer  block  is  of  granite  and  the  reinforcement  of  the  post 

138 


consists  of  8o-pound  rails  connected  with  i%-inch  tie  rods.     The  footing  of 
the  post  is  carried  down  to  solid  foundation. 


Granite 


^ 

ii^ 

7 

r-a 

, 

cr. 

f--  =----- 

fcfell^" 

-a-. 

^ 

^-r_r- 

-- 

•  3fL-9'^ 

k/^ 

K. 


r^/^  PLAN 


^ 


i 


m  •*& 


O 

o 


gp=f^ 


•^    '^^K^    v    « 

////A  VN0'-     \     c\, 

///  i>  \\VNN  <s^    x 


FRONT  ELEVATION  SECT/ ON 

FIG.  103.— STANDARD  CONCRETE  BUMPING  POSTS,  D.,  L.  &  W.  P.  P. 


139 


140 


CHAPTER  XI. 


POWER  STATIONS,  SHOPS,  WAREHOUSES  AND  GRAIN  ELEVA- 

VATORS. 

POWER  STATIONS. 

The  electrification  of  railroad  systems,  which  bids  fair  to  be  a  thing  of  the 
near  future,  will  necessitate  the  construction  of  a  large  number  of  power  sta- 
tions along  the  lines  of  the  railroads  adopting  this  form  of  motive  power. 

Concrete  construction  in  addition  to  its  low  first  cost,  facility  of  erection 
and  fireproof  character  is  especially  adapted  to  the  building  of  power  plants 
on  account  of  its  inherent  strength,  resistance  to  vibrations  and  freedom  from 
deterioration. 

The  New  York,  New  Haven  and  Hartford  Railroad,  one  of  the  earliest 
pioneers  in  the  field  of  heavy  electric  traction,  has  installed  electric  equipment 
on  its  lines  from  Woodlawn,  N.  Y.,  to  Stamford,  Conn.,  with  the  power  sta- 
tion for  this  twenty  miles  of  road  located  at  Cos  Cob,  about  three  miles  from 
Stamford.  This  power  house  described  below  is  of  concrete  construction  and 
is  a  noteworthy  example  of  the  pleasing  appearance  which  can  be  given  to  a 
purely  utilitarian  structure  by  engineers  who  pay  special  attention  to  the  arch- 
itectural treatment  of  their  designs. 

COS  COB  POWER  PLANT,  N.  Y.,  N.  H.  &  H.  R.  R.  The  power  house 
is  located  at  Cos  Cob,  three  miles  west  from  Stamford,  on  the  Mianus  River, 
about  a  mile  from  Long  Island  Sound.  The  engineers  in  charge  of  the  design 
and  construction  of  the  plant  adopted  the  Spanish  Mission  style  of  architect- 
ure for  the  exterior  of  the  building,  with  a  very  pleasing  result.  The  interior 
is  divided  into  a  turbine  room  60  feet  wide  by  112  feet  long,  with  a  switch- 
board occupying  an  additional  space  of  25  feet  by  no  feet  and  a  boiler  room 
160  feet  long  by  no  feet  wide. 

The  photograph  in  Fig.  105  shows  the  track  side,  while  Fig.  104  is  of  the 
water  side  of  the  power  house. 

The  foundations,  column  footings  and  walls  up  to  the  water  table  are 
monolithic  concrete  mixed  in  the  proportions  of  i  part  Atlas  Portland 
Cement,  3  parts  sand  and  5  parts  2-inch  crushed  granite.  All  exposed  sur- 
faces of  the  walls  have  a  bush-hammered  finish.  For  the  water-table,  window 

141 


142 


arches,  coping  and  window  sills,  monolithic  blocks  are  used.  These  blocks, 
are  built  in  special  shapes  and  are  made  of  concrete  of  the  same  proportions  as 
the  other  monolithic  work,  and  have  the  inner  and  outer  surfaces  faced  with  a 
mixture  of  i  part  cement  to  2  parts  sand. 

The  walls  above  the  water-table  are  of  hollow  blocks,  10  in.  by  12  in.  by  24 
in.,  composed  of  a  mixture  of  i  part  cement,  3  parts  sand  and  3  parts  i  ^4-inch 
crushed  granite,  faced  on  the  exterior  surface  with  a  mixture  of  i  of  cement  to 
2  of  sand,  and  where  the  inner  surface  of  the  wall  is  exposed  with  a  mixture  of 
i  part  cement  to  4  parts  sand.  All  the  window  lintels  were  cast  in  place,  and 
consist  of  i  :3 15  concrete  reinforced  with  two  3^-trussed  bars. 


Trussed  Bars     =  E 


2.6m. 


RtPRODUCE-D      FROM    DESIGNS 

OF 
WE1STINGHOUSEL,     CH  URC  H,   KERR  Q.  CO. 

FIG.  106.— CROSS  SECTION  THROUGH  TURBINE  ROOM,  COS  COB  POWER  PLANT. 

In  designing  the  structural  features  of  the  building,  the  following  live  loads 
per  square  foot  were  used:  Coal  bin  floor,  550  pounds;  engine  room  and  gal- 
iery  floors,  400  pounds;  boiler  room  floor,  340  pounds;  fan  room  floor,  200 
pounds;  roof,  30  pounds.  With  the  exception  of  the  roof  slabs,  which  are  of 
cinder  concrete,  the  stresses  allowed  for  the  concrete  are  600  pounds  per  square 


inch  extreme  fiber  stress,  400  pounds  per  square  inch  direct  compression,  and 
60  pounds  per  square  inch  shear,  and  for  the  steel  a  tensile  stress  of  16,000 
pounds  was  assumed. 

The  columns  in  the  boiler  room  are  of  structural  steel,  but  all  other  col- 
umns in  the  building  are  composed  of  concrete  blocks  made  by  filling  the  cored 
air  spaces  of  the  hollow  blocks  with  concrete  of  the  same  mixture  as  the  blocks 
themselves.  Over  the  turbine  room  where  there  are  no  steel  columns  the 
steel  roof  trusses  are  carried  by  the  concrete  block  wall,  the  blocks  being  solid 
for  several  courses  below  trusses  to  properly  distribute  the  load.  Over  the 


FIG.  107.— TURBINE  ROOM,  COS  COB  POWER  PLANT. 

boiler  room  the  trusses  are  supported  in  the  same  way  and  also  by  the  interior 
steel  columns. 

The  front  of  the  switchboard  gallery,  at  one  end  of  the  turbine  room,  is 
carried  on  concrete  block  columns,  which  also  support  a  reinforced  concrete 
girder  forming  one  of  the  crane  runways,  which  carry  an  electric  traveling 
crane,  provided  with  two  ly^-ton  trolleys.  The  other  crane  runway  is  formed 
by  a  similar  girder  built  into  the  partition  wall  between  the  engine  room  and 
boiler  room,  and  is  carried  by  pilasters  formed  in  this  wall.  These  girders 
furnish  a  rather  unique  feature,  for  while  they  are  essentially  concete  girders 

M4 


36  by  36  inches  reinforced  with  trussed  bars,  they  are  built  with  the  bottom 
slightly  arched  and  the  sides  and  bottoms  ribbed  to  imitate  keystone  and  vous- 
soirs,  the  whole  giving  the  appearance  of  a  segmental  arch.  The  girders  are 
shown  clearly  in  the  photograph  of  the  turbine  room  in  Fig.  107  and  by  the 
drawings  in  Fig.  106,  which  are  of  a  cross  section  taken  through  the  turbine 
room. 

With  the  exception  of  the  basement  floor,  which  is  1 13 15  concrete  laid 
directly  upon  the  foundation  rock,  the  floor  system  consists  of  concrete  slabs, 
reinforced  with  twisted  steel  rods,  carried  on  the  top  flanges  of  I-beams.  These 
slabs  were  mixed  in  the  proportions  of  i  part  cement,  3  parts  sand  and  5  parts 
24-inch  broken  stone  with  a  i-inch  granolithic  finish  applied  before  the  under- 
lying concrete  had  time  to  dry.  After  the  floors  had  dried  out  they  were 
given  two  coats  of  linseed  oil  and  lampblack.  In  the  engine  room  the  floor 
finish  is  carried  up  at  the  side  walls  and  columns  to  form  a  base  10  inches  high 
and  1 3/4  thick  for  a  6  foot  wainscoting  of  Faience  tile.  Above  this  wainscoting 
the  walls  are  unfinished  except  for  a  cement  wash. 

The  roof,  which  has  a  pitch  of  4^/2  inches  per  foot,  is  of  1 12  14  cinder  con- 
crete laid  between  3-inch  5^-pound  I-beam  purlins  3  feet  on  centers,  and  is 
finished  on  the  exterior  with  red  Ludowici  interlocking  tiles  set  on  i  inch  by 
2  inch  strips  24  inches  on  centers,  and  secured  thereto  by  means  of  staples 
and  copper  wire.  Between  the  tiles  and  the  concrete  there  is  one  thickness  of 
tarred  paper. 

A  self-supporting  steel  stack  13  feet  6  inches  in  diameter  and  46  feet  high 
is  carried  by  the  steel  columns  which  support  the  fan  room  floor,  thus  leaving 
the  space  below,  in  the  boiler  room,  entirely  clear. 

Work  on  the  power  house  was  started  Feb.  3d  and  steam  was  turned  on 
Nov.  4,  1906.  The  construction  plant  consisted  of  one  3/£  and  one  i  ^4-yard 
mixers,  a  stone  crusher,  3  boom  derricks,  a  temporary  power  plant, 
buckets,  etc.,  and  two  block  machines.  The  material  excavated  was  a 
gneiss  rock,  and  furnished  after  crushing  and  screening  all  the  broken  stone 
for  the  building,  and  a  sufficient  quantity  of  screenings  to  take  the  place  of 
sand  for  the  exterior  walls.  For  the  wall  forms  2-inch  matched  spruce  was 
used  and  for  the  floor  and  roof  slab  forms  i-inch  matched  spruce.  The  mono- 
lithic blocks  which  were  molded  in  pine  forms,  well  greased,  were  mixed  very 
wet,  and  after  the  removal  of  the  forms  were  stored  under  canvas  24  hours  and 
then  left  in  the  open  for  three  weeks.  After  the  hollow  blocks  were  turned  out 
of  the  machine  they  were  cured  in  the  same  manner. 

The  plant  was  designed,  erected  and  equipped  by  the  Westinghouse, 
Church-Kerr  Company  under  the  direction  of  Mr.  E.  H.  McHenry,  Vice- 
President  of  the  New  York,  New  Haven  and  Hartford  Railroad. 


SHOPS  AND  WAREHOUSES. 

The  same  advantages  which  reinforced  concrete  possesses  over  other  ma- 
terials for  the  construction  of  power  houses  are  equally  enjoyed  by  it  as  a 
material  for  shop  and  warehouse  buildings  for  railway  purposes. 


FIG.  108.— BOGALUSA  SHOPS^DURING  CONSTRUCTION,  N.  O.  &  G.  N.  R.  R. 

The  field  of  reinforced  concrete  in  shop  and  warehouse  construction  is  so 
vast  that  it  is  impossible  to  even  attempt  to  cover  it  in  this  chapter,  but  the 
reader  is  referred  to  "Reinforced  Concrete  in  Factory  Construction,"  published 
by  The  Atlas  Portland  Cement  Company,  as  a  more  complete  treatise  on  the 
subject. 

In  addition  to  the  structures  described  and  illustrated  below,  there  are  a 
number  of  shops,  freight  sheds,  warehouses  and  inspection  sheds  shown 
among  the  miscellaneous  photographs  in  the  back  of  the  book.  ;  „' 

N.  O.  &  a  N.  R.  R.  SHOP  AND  STORE  HOUSE,  BOGALUSA,  LA.— 
The  photograph  in  Fig.  108  shows  one  of  the  shops  during  construction  and 
Fig.  109  is  of  the  finished  store  house  of  the  New  Orleans  and  Great  Northern 
Railroad  at  Bogalusa,  La.  With  the  exception  of  the  roof,  these  buildings 

146 


are  of  concrete  construction  throughout.    They  were  designed  and  erected  by 
the  Arnold  Company  of  Chicago  in  1907. 


FIG.   109.— STOREHOUSE,  BOG  AL  US  A,  LA.,  N.  O.   &  G.  N.  R.  R. 


MOTT  HAVEN  CAR  SHOPS,  N.  Y.  C.  &  H.  R.  R.  R.— The  Mott  Haven 
shops  are  250  feet  long,  43  feet  10  inches  wide,  and,  as  will  be  seen  from  the 
photograph  in  Fig.  no,  they  are  built  in  alternate  high  and  low  bays,  the 
former  25  feet  high  and  the  latter  19  feet  4  inches.  As  windows  are  provided 
in  each  side  of  the  high  bays  above  the  roof  of  the  low  ones,  this  construction 
takes  the  place  of  the  ordinary  saw-tooth  roof. 

In  general,  the  buildings  consist  of  2^-inch  cement  mortar  curtain  walls 
reinforced  with  truss  metal  lath,  No.  28  gage,  resting  on  a  concrete  foundation 
wall  rising  4  feet  above  the  ground  level.  The  roof  is  carried  on  light  angle 
trusses  supported  by  I-beam  columns  placed  every  16  feet  8  inches  at  the 
division  between  the  adjoining  high  and  low  sections.  Between  the  columns 
and  window  frames  steel  girts  are  placed  to  form  a  support  for  the  truss  metal 
lath  reinforcement  of  the  walls. 

The  metal  lath  was  kept  in  place  and  held  rigidly  by  means  of  temporary 
i  by  i  inch  angles  spaced  about  2  feet  apart.  The  mortar,  which  was  mixed 


in  the  proportion  of  one  part  Atlas  Portland  Cement  to  three  parts  sand,  was 
placed  in  the  same  manner  as  plaster  for  an  ordinary  wall. 

The  shops  were  designed  and  erected  in  1908  under  the  supervision  of  the 
engineering  department  of  the  New  York  Central  &  Hudson  River  R.  RM 
Mr.  G.  W.  Kittredge,  Chief  Engineer.  The  Truss  Metal  Lath  Company,  New 
York  City,  furnished  the  reinforcing  material  and  built  the  walls  of  the 
building. 


FIG.  110.— CAR  SHOPS,  MOTT  HAVEN,  N.  Y.  C.  &  H.  R.  R.  R. 

NEWARK  WAREHOUSE,  C.  R.  R.  of  N.  J.— This  mammoth  seven- 
floor  warehouse,  a  photograph  of  the  track  side  of  which  is  shown  in  Fig.  in, 
is  360  feet  long  with  a  width  varying  from  130  to  165  feet,  and  has  a  storage 
capacity  of  about  1,200  carloads  of  freight.  The  first  floor  is  devoted  to 
teaming,  the  second  to  the  freight  tracks,  and  the  basement  and  four  top  floors 
to  storage. 

In  general,  the  building  consists  of  a  steel  frame  and  concrete  walls,  with 
steel  columns  and  girders  carrying  floor  slabs  of  reinforced  concrete.  Owing 
to  the  presence  of  quicksand,  an  exceptionally  wide  spread  of  footings  was 
required,  which  resulted  in  the  engineers  making  the  foundation  one  continu- 
ous plate  of  concrete  15  inches  thick  reinforced  with  extra  heavy  expanded 
metal. 

148 


The  walls,  which  are  embellished  with  rustications,  moldings,  dentils  and 
cornices,  are  20  inches  thick  to  the  second  story,  16  inches  thick  to  the  third 
story,  and  12  inches  thick  from  there  up  to  the  top.  The  reinforcement  for 
the  walls  consists  of  expanded  metal  and  3/^-inch  rods  laid  horizontally  about 
4  feet  apart. 

The  concrete  for  the  walls,  floor  slabs,  column  covering  and  roof  slabs, 
was  mixed  in  the  proportions  of  one  part  Atlas  Portland  Cement,  to  2  parts 
Cowe  Bay  washed  sand,  to  4  parts  %-inch  crushed  stone. 


FIG.  111.— NEWARK  WAREHOUSE,  C.  R.  R.  OF  N.  J. 

The  warehouse  was  designed  and  constructed  under  the  general  direction 
of  Mr.  Jos.  O.  Osgood,  Chief  Engineer  of  the  C.  R.  R.  of  N.  J.,  by  the  John  W. 
Ferguson  Co.,  Paterson,  N.  J.,  in  1907. 

PORT  MORRIS  BOILER  HOUSE,  D.,  L.  &  W.  R.  R.— The  photograph 
in  Fig.  112,  page  150,  shows  a  boiler  house  of  heavy  concrete  construction 
built  at  Port  Morris,  N.  J.,  for  the  Deleware,  Lackawanna  &  Western  R.  R. 

LOADING  PLATFORM,  SIOUX  CITY,  IA.— In  connection  with  ware- 
houses and  storage  sheds,  the  construction  of  loading  platforms  is  of  special 
interest.  The  photograph  in  Fig.  113,  page  150,  shows  a  reinforced  concrete 
platform  164  feet  long  and  14  feet  wide,  which  was  constructed  in  1908  at  a 
cost  of  $2,500. 

149 


FIG.  112.— PORT  MORRIS  ^BOILER-HOUSE,  D.,  L.  &  W.  R.  R. 


FIG.  113.— LOADING  PLATFORM,  SIOUX  CITY    IA, 
ISO 


GRAIN   ELEVATORS. 

Reinforced  concrete  is  especially  adapted  to  the  construction  of  grain 
elevators  or  other  structures  to  be  used  for  the  storage  of  grain  on  account 
of  its  being  absolutely  proof  against  fire,  water  or  dampness,  dust  and  vermin ; 
which  are  all  important  and  essential  qualities  of  the  ideal  grain  elevator. 


FIG.  114. -TYPICAL  CONCRETE  GRAIN  ELEVATOR. 

Grain  elevators  may  be  grouped  into  two  classes  according  to  the  arrange- 
ment of  the  bins  and  elevating  machinery;  viz.,  elevators  which  are  self-con- 
tained, with  all  the  storage  bins  in  the  main  elevator  or  working  house;  and 
elevators  consisting  of  a  working  house  which  contains  the  elevating  ma- 
chinery and  storage  bins  connected  with  the  working  house  by  conveyors. 
Reinforced  concrete  elevators  are  commonly  built  of  the  latter  type,  with  a 
working  house  that  is  generally  rectangular  in  shape  with  either  square  or 
circular  bins  connected  with  the  independent  storage  bins,  which  are  usually 
circular.  The  photograph  in  Fig.  114  is  of  a  reinforced  concrete  elevator  of  the 
type  built  by  the  James  Stewart  &  Co.,  of  Chicago. 

In  elevators  of  this  type  the  storage  bins  are  reinforced  both  horizontally 
and  vertically.  The  horizontal  reinforcement  is  either  single  when  it  is  placed 


in  the  center  of  the  wall,  as  in  Fig.  115,  or  double  when  the  bars  are  placed  near 
the  surface.  This  reinforcement  may  be  continuous,  rising  from  the  bottom 
to  the  top  as  a  spiral,  in  which  case  high  steel  wire  is  generally  used,  or  may 


T/ON     THROUGH,     TANKS 

FIG.  115.— CROSS  SECTION  OF  TYPICAL  REINFORCED  CONCRETE  GRAIN  ELEVATOR. 

be  placed  in  separate  rings,  as  in  Fig.  117.  The^ vertical  reinforcing  bars  are 
equally  spaced,  and  are  wired  or  clamped  to  the  horizontal  rods  at  intersec- 
tions. 

The  horizontal  reinforcement  is  generally  designed  to  take  all  the  tensile 
stresses  resulting  from  the  pressure  of  the  grain,  while  the  vertical  reinforce- 

152 


153 


ment  carries  the  load  between  the  horizontal  reinforcement,  and  takes  its  pro- 
portion of  the  vertical  load.  The  walls  have  a  negative  bending  moment  at 
the  points  of  horizontal  reinforcement,  and  a  positive  bending  moment  half- 
way between  the  horizontal  reinforcement.  The  pressure  on  any  horizontal 
section  equals  the  weight  of  the  wall  plus  the  weight  of  the  grain  carried  by 
the  walls,  and  this  pressure  is  carried  by  both  the  concrete  and  the  steel. 
While  the  space  here  is  too  limited  to  go  into  the  discussion  of  the  theory 


FIG.  117.— SECTION  THROUGH  BINS,  TYPICAL  CONCRETE  GRAIN  ELEVATOR. 

of  the  pressure  in  grain  bins  or  to, give  the  methods  employed  in  designing 
the  structural  features  of  reinforced  concrete  grain  elevators,  the  reader  is 
referred  to  "The  Design  of  Walls,  Bins  and  Grain  Elevators,"  by  Milo  S. 
Ketchum,  as  a  complete  treatise  on  the  subject. 

Among  the  miscellaneous  photographs  in  the  back  of  the  book  are  shown 
a  number  of  reinforced  concrete  grain  elevators  of  different  types. 

154 


CHAPTER    XII. 
STORAGE    RESERVOIRS. 

The  advent  of  power  construction  into  the  field  of  railroad  engineering 
incidentally  introduces  another  problem  for  railroad  engineers  in  the  subject 
of  storage  reservoirs  for  supplying  these  plants  with  water. 

Reinforced  concrete  has  been  used  extensively  in  the  construction  of  reser- 
voirs and  when  properly  designed  and  constructed  is  a  most  suitable  material 
on  account  of  its  durability  and  adaptability  to  lighter  design  than  common 
masonry.  For  large  or  small  tanks  it  is  usually  cheaper  than  steel  and  requires 
no  repairs. 

Reservoirs  are  built  most  economically  of  circular  form,  and  all  the  tensile 
stresses  must  be  taken  by  the  steel  hoops. 

In  buildng  water  tanks,  the  materials  for  the  concrete  must  be  very  care- 
fully proportioned  so  as  to  give  a  water-tight  wall  and  the  stone  should  be  of 
such  size  that  a  good  surface  can  be  easily  obtained.  The  proportions  used 
to  resist  the  percolation  of  water  usually  range  from  1:1:2  to  1:2^:4^2,  the 
most  common  mixture  being  1 12  14. 

The  concrete  should  be  mixed  so  that  it  will  entirely  cover  the  reinforcing 
metal  and  flow  against  the  form.  It  is  absolutely  essential  that  the  concreting 
for  the  entire  tank  should  be  done  in  one  operation,  or  else  that  the  surface  be 
specially  prepared  and  treated  to  make  water-tight  joints. 

COS  COB  STORAGE  RESERVOIR.— In  connection  with  the  power 
plant  of  the  New  York,  New  Haven  &  Hartford  R.  R.  at  Cos  Cob,  Conn., 
described  in  Chapter  XI,  there  is  a  564,000  gallon  reinforced  concrete  storage 
reservoir  80  feet  in  diameter  and  15  feet  deep.  The  architectural  treatment 
of  the  exterior  of  the  reservoir  is  in  keeping  with  that  of  the  power  house  and 
presents  a  very  attractive  appearance.  As  will  be  seen  from  the  photograph 
in  Fig.  119  and  the  section  in  Fig.  118,  the  wall  has  a  cornice  projecting  13% 
inches  and  a  base  7^/2  inches,  while  the  flat  space  between  is  relieved  with  a 
series  of  forty  arched  indented  panels.  To  further  the  effect  of  these  arched 
panels,  the  face  of  the  concrete  of  the  indented  surface  is  roughened,  and  the 
remainder  of  the  exterior  is  given  a  smooth  cement  mortar  finish. 


\  4P/y  Hycfrcx  fe/t 


RCPRODUCED      FROM   DESIGNS 

or 

WESTINGHOUvSE,    CHURCH,  KERR     a    CO. 
FIG.  118.— SECTION  THROUGH  WALL,  COS  COB  STORAGE  RESERVOIR. 

156 


All  the  concrete  was  mixed  in  the  proportions  of  i  part  Atlas  Portland 
Cement,  3  parts  sand  and  5  parts  3/^-inch  crushed  granite.  The  wall  is 
reinforced  circumferentially  with  the  cast  steel  transmission  rope,  varying  in 
diameter  from  1^/2  inches  at  the  base  to  ^g  inches  at  the  top,  forming  a  con- 
tinuous spiral  with  12  foot  splices  made  with  16  clips  where  the  ends  of 
different  sizes  of  cable  are  joined.  Wired  to  the  inside  of  this  rope  spiral 
is  a  continuous  sheet  of  3  by  1 2-inch  mesh  wire  cloth,  placed  in  vertical 


FIG.  119.— COS  COB  STORAGE  RESERVOIR,  N.  Y.,  N.  H.  &  H.  R.  R. 

strips  and  extending  6  feet  into  the  floor  of  the  reservoir.  The  wall  and  floor 
is  waterproofed  with  4-ply  felt  cemented  together  with  a  patented  com- 
pound. On  the  floor  of  the  tank  a  4-inch  protective  covering  of  concrete  was 
laid  on  top  of  the  waterproofing,  and  carried  up  the  wall  16  inches  at  an  angle 
of  45°,  to  form  a  footing  for  a  4-inch  lining  of  brick  laid  up  in  cement  mortar 
that  protects  the  waterproofing  coat  of  the  wall.  The  dimensions  and  general 
features  of  design  of  the  reservoir  are  clearly  shown  in  Fig.  118. 

A  lo-inch  inlet  and  a  1 2-inch  outlet  pipe  enter  through  the  floor  of  the 
tank,  and  where  they  pass  through  the  waterproofing,  watertight  connections 
are  secured  by  clamping  a  sheet  of  soft  copper  between  two  flanged  screw 
sleeves,  as  shown  in  Fig.  120.  About  a  foot  outside  the  reservoir  wall  these 


pipes  run  into  a  concrete  valve  chamber  n  feet  4  inches  long,  5  feet  8  inches 
wide,  and  5  feet  3  inches  high,  in  the  top  of  which  is  a  3O-inch  manhole  having 
an  American  Brake  Shoe  and  Foundry  Company's  standard  manhole  frame 
and  cover.  A  3-inch  steam  pipe  runs  from  the  power  house  through  the  valve 
chamber  and  into  the  tank  where  it  is  carried  half  way  across  the  floor  on 
small  brick  piers  6  feet  on  centers.  This  pipe  has  a  perforated  upturned  end 
so  as  to  keep  the  water  above  the  freezing  point  in  cold  weather. 

In  building  the  tank,  the  forms  for  the  exterior  wall  were  erected  complete 
from  the  foundations  to  the  coping.  The  spiral  rope  reinforcing  was  then 
hung  on  screw  hooks  driven  into  the  inner  surface  of  these  forms  and  the 


REPRODUCED    THOU  DESIGNS 

or 
WE5TIIMGHOU3E,  CHURCH,  KERR     4CO. 


FIG.  120.— SECTION  THROUGH  VALVE  CHAMBER,  COS  COB  STORAGE  RESERVOIR. 


wire  cloth  was  wired  to  the  spiral.  The  inside  forms  were  built  up  a  few 
feet  at  a  time,  and  were  wired  through  the  vertical  supports  to  the  outer  forms. 
The  concrete  was  mixed  in  a  54  yard  rotary  mixer  located  just  outside 
the  reservoir,  and  was  carried  inside  in  i  yard  skips  by  a  guyed  derrick  placed 
in  the  center  of  the  tank  and  operated  by  a  hoisting  engine  standing  outside. 
The  derrick  cables  were  run  through  holes  in  the  wall  which  were  filled  in 
after  the  forms  were  removed.  Two  weeks  after  concreting  the  walls  the 
forms  were  removed,  the  derrick  taken  out,  and  the  waterproofing  was  applied 
as  described  above. 

158 


The  reservoir  was  designed  and  erected  by  Westinghouse,  Church,  Kerr 
&  Co.,  of  New  York,  the  engineers  and  constructors  of  the  power  plant. 

PITTSBURG  STORAGE  RESERVOIR,  KANSAS  CITY  SO.  RY.— 
This  reservoir,  85  feet  in  diameter,  which  serves  as  a  storage  supply  for  the 
Kansas  City  Southern  Railway  shops  at  Pittsburg,  Kan.,  is  shown  by  the 


FIG.  121.— PITTSBURG  STORAGE  RESERVOIR,  K.  C.  S.  RY. 

photograph  in  Fig.  121.  The  reservoir  rests  on  a  puddle  clay  bottom,  on  which 
a  6-inch  cinder  fill  is  placed,  and  has  a  concrete  wall  4  inches  thick  mixed  in 
the  proportions  of  one  part  Atlas  Portland  Cement  to  2  parts  sand  to  4 
parts  broken  stone,  with  a  %-inch  i  :i  mortar  finish.  The  total  cost  of  the 
reservoir,  which  included  1,500  yards  of  mass  concrete  in  addition  to  66  cubic 
yards  of  1 12  .-4  concrete,  was  $736.  The  Arnold  Company  of  Chicago  were  the 
engineers  in  charge  of  the  design  and  construction. 


sC-^-/i*ril*£.*jC*X 


160 


CHAPTER   XIII. 

DOCKS. 

Inasmuch  as  practically  every  railroad  system  in  the  country  owns  valu- 
able water  front  the  question  of  dock  construction  is  a  most  important  one. 
The  recent  terrible  fires  with  their  attendant  devastation  along  the  water 
fronts  of  Hoboken  and  of  Boston  have  demonstrated  only  too  clearly  the 
absolute  necessity  of  positive  fire  protection  in  structures  of  this  nature.  The 
new  piers  which  the  Delaware,  Lackawanna  and  Western  Railroad  have  de- 
signed to  replace  those  burned  down  in  the  Hoboken  fire  of  1904  are  to  be 
built  entirely  of  concrete  construction  from  the  cut-off  of  the  piles.  This  type 
of  pier,  which  is  described  below,  is  proof  against  fire  and  decay  and  should 
be  practically  free  from  maintenance. 

In  the  tropics  where  the  waters  are  infested  with  limnoria  and  teredos 
which  destroy  a  wooden  pile  in  a  few  years  and  where  the  very  atmosphere 
itself  eats  away  unprotected  wooden  and  steel  structures  reinforced  concrete 
is  especially  adapted  to  the  construction  of  wharves  and  warehouses.  Prac- 
tically all  the  docks  of  any  magnitude  now  being  constructed  in  South  and 
Central  America  and  the  Philippines  are  designed  as  entire  concrete  struc- 
tures. 

The  Almirante  wharf  of  the  Changuinola  Railroad  at  Bocas  del  Toro, 
Panama,  described  on  page  163,  is  an  interesting  example  of  this  type  of  con- 
struction. 

HOBOKEN  PIER,  NO.  7,  D.,  L.  &  W.  R.  R.— This  pier,  which  is  the 
first  of  a  series  to  be  built  on  the  same  general  scheme  along  a  railway  yard 
ship  canal,  is  100  feet  wide  and  600  feet  long. 

As  will  be  seen  from  the  transverse  section  of  the  pier,  shown  in  Fig.  122, 
the  construction  in  general  consists  of  a  6-inch  concrete  floor  carried  on  a 
cinder  fill  retained  between  concrete  face  walls  and  supported  on  a  solid  tim- 
ber of  grillage  carried  on  piles  cut  off  at  low  water  level. 

These  piles,  which  are  from  85  to  95  feet  in  length,  are  driven  3  feet  apart 
in  transverse  rows  5  feet  apart.  Each  pile  is  proportioned  for  a  maximum 
load  of  12  tons.  At  mean  low  water  they  are  capped  with  continuous,  12  by 
i2-inch  transverse  timbers,  drift  bolted  to  them.  Spiked  to  these  caps  are 
longitudinal  6  by  1 2-inch  planks  laid  close  to  form  the  deck.  On  either  side 

161 


of  the  pier  the  outer  planks  alternate  with  three  12  by  1 2-inch  longitudinal 
timbers  which  project  above  the  top  of  the  deck  and  form  ribs  to  prevent  the 
concrete  side  walls  from  slipping  or  transverse  displacement. 

The  steel  shed  and  platform  are  carried  on  concrete  piers  and  longitudinal 
walls  which  are  built  about  u  feet  high  to  the  level  of  the  pier  floor.     The 


FIG.^123. — HOBOKEN£PIER^DURING  CONSTRUCTION. 


photograph  in  Fig.  123  shows  one  side  wall  and  one  row  of  intermediate  piers 
during  construction. 

The  space  between  the  side  walls  is  filled  with  rolled  cinders  about  gT/2 
feet  deep  under  the  shed  and  6  feet  deep  outside  where  the  railroad  tracks  are 
laid  directly  on  it. 

The  pier  shed  shown  in  elevation  by  the  photograph  in  Fig.  124,  and  in  sec- 
tion by  the  drawings  in  Fig.  122,  is  59^2  feet  wide  and  594  feet  long,  and  con- 
sists of  a  6-inch  concrete  floor  without  surface  finish  laid  directly  on  the 
cinder  fill  with  a  superstructure  of  steel  framework  carrying  reinforced  con- 
crete walls  and  roof. 

In  connection  with  the  side  walls,  the  provision  made  to  allow  for  the 
future  adjustment  of  the  walls  presents  an  interesting  and  important  feature 
in  construction  of  this  type  where  settlement  of  foundation  is  liable  to  occur. 

162 


The  foot  of  the  wall,  which  is  6  inches  thick,  is  built  in  a  slot  in  the  concrete 
floor  6  inches  deep  and  7  inches  wide.  Two  thicknesses  of  tarred  paper  sep- 
arate the  wall  from  the  floor  thus  preventing  the  possibility  of  adhesion 
between  the  two  concrete  surfaces,  so  that  the  wall,  although  having  a  clear- 
ance of  ^2-inch  on  each  side  of  the  slot,  is  held  securely  against  transverse 
displacement  and  forms  a  closed  point  at  the  bottom,  the  upper  edges  of  the 
crack  being  caulked  with  oakum  and  pointed  with  cement  mortar. 


FIG.  124.— PIER  SHED,  HOBOKEN  PIER,  D.,  L.  &  W.  R.  R. 

If  settlement  occurs,  the  wall  and  the  steel  superstructure  will  be  jacked 
up  to  level  the  roof  and  the  openings  on  each  side  of  the  slot  in  the  floor  will 
be  recaulked  and  repointed  thus  restoring  the  ordinary  appearance  of  the  wall. 

The  shed  is  divided  approximately  into  equal  parts  by  a  transverse  rein- 
forced concrete  fire  wall  12  inches  thick. 

The  pier  and  shed  were  designed  by  the  engineering  department  of  the 
Delaware,  Lackawanna  and  Western  Railroad,  Mr.  Lincoln  Bush,  Chief  En- 
gineer, and  Mr.  G.  T.  Hand,  assistant  engineer  in  charge  of  design,  and  the 
general  contractor  was  Mr.  Henry  Steers,  of  New  York  City. 

ALMIRANTE  WHARF,  BOCAS  DEL  TORO,  PANAMA.— This  wharf 
which  is  at  the  terminus  of  the  Changuinola  Railroad,  Almirante,  Bocas  del 

163 


Toro,  Panama,  is  of  special  interest  owing  to  the  fact  that  it  is  of  reinforced 
concrete  throughout  and  that  in  its  construction  the  problem  of  pile  protec- 
tion in  the  tropics  has  been  successfully  solved. 

It  is  approximately  700  feet  long  and  54  feet  wide  and  is  connnected  with 
the  mainland  by  a  creosoted  timber  trestle  approach  about  800  feet  in  length. 
The  photograph  in  Fig.  125  shows  one-half  of  the  shore  side  of  the  wharf. 


FIG.  125.— ALMIRANTE  WHARF,  BOCAS  DEL  TORO,  PANAMA. 

As  the  purpose  of  the  wharf  is  the  loading  of  bananas  onto  the  outgoing, 
and  the  temporary  storage  of  general  merchandise  received  from  the  incoming, 
steamers,  the  front  of  the  wharf  for  a  distance  of  23  feet  is  open  to  allow  the 
free  use  of  automatic  loading  machines,  while  the  remainder  is  covered  with  a 
steel  storage  shed,  open  6  feet  from  the  bottom  in  the  rear  and  14  feet  in  the 
front.  The  bananas  are  carried  to  the  loading  machines  by  a  3-foot  gauge 
track  in  front  connected  by  cross-overs  to  two  similar  tracks  running  the 
length  of  the  storage  shed. 

As  will  be  seen  from  the  cross  section  in  Fig.  126,  which  shows  the  essential 
details  of  design  and  construction,  the  wharf  consists  of  a  series  of  reinforced 
concrete  columns  supporting  a  system  of  main  girders  and  cross  beams  which 
in  turn  carry  a  7-inch  floor  slab.  The  columns  rest  on  wooden  piles  spaced 
10  feet  on  centers,  protected  by  a  four-inch  covering  of  concrete. 

This  method  of  protecting  the  wooden  piles  from  the  attacks  of  teredos 


consisted  in  driving  a  2-inch  concrete  shell — 20  inches  in  diameter  at  the  top 
and  1 6  inches  at  the  bottom  reinforced  its  full  length  with  4-inch  by  1 2-inch 
wire  cloth  over  the  wooden  pile  and  into  the  harbor  bottom  two  feet. 
The  shell  was  then  sealed  at  the  bottom  with  concrete,  the  water  pumped 
out  and  the  intermediate  space  between  the  shell  and  the  pile  filled  with  con- 
crete to  the  level  of  the  top  of  the  shell  which  was  about  2  feet  above  the  top 
of  the  pile  and  i  foot  above  high  water.  The  shells  were  made  in  lengths 


3 - Roofs 

2- Rods 


^l"Hbds 
TRANSVERSE  SECT/ ON 


mn 
Mean  Sea  Leve/ 


FIG.  126.— CROSS  SECTION,  ALMIRANTE  WHARF. 

varying  from  32  feet  to  12  feet  according  to  the  depth  of  water  and  were  com- 
posed of  concrete  mixed  in  the  proportions  of  i  part  Portland  cement  to  2 
parts  of  crusher  dust  to  3  parts  of  J^-inch  broken  stone,  and  the  filling  con- 
sisted of  concrete  mixed  in  the  proportions  of  1 12  14. 

In  constructing  the  columns,  girders  and  beams,  a  mixture  of  i  of  ce- 
ment to  2  of  sand  to  2  of  crusher  dust  to  3  of  i-inch  broken  stone  was  used 
and  for  the  floor  slabs  a  mixture  of  1 12  :i  13  of  the  same  materials. 

The  reinforcing  rods  for  the  columns  were  embedded  four  feet  in  the  fill- 
ing between  the  shells  and  the  piles  and  were  carried  up  through  the  main 
girders  and  into  the  floor  slab,  thus  securely  tieing  together  the  entire  struc- 
ture. For  the  columns,  main  girders  and  railroad  beams,  ^4-inch  round  rods 
were  used  for  reinforcing,  and  for  the  floor  slab,  ^-inch  round  rods. 

165 


Fig.  127  shows  in  detail  the  ship  buffer,  which  consists  of  two  8  by  1 2-inch 
creosoted  timbers  protected  by  2  by  lo-inch  wearing  strips  every  3  feet  4  inches 
with  a  railroad  car  spring  of  19,000  pounds  resistance,  resting  in  a  cast  steel 
socket  embedded  in  the  concrete  at  each  bent  to  take  the  shock. 

Every  50  feet,  hollow  steel  mooring  bits  were  placed  on,  and  bolted  to,  con- 
crete pedestals  and  were  then  filled  with  concrete  as  shown  by  the  detail  in 
Fig.  127. 

With  the  exception  of  general  foremen,  native  and  Jamaican  labor  was 
used  throughout,  both  for  building  the  forms,  placing  the  concrete  and  erecting 
the  steel  shed. 


) 


2" 

L 

—  20     -- 

\ 

^ 

o 

K 

Loop 
Rods  6"CtoC 

1 


/-4.//M 

Spring  JSOOO/bs.ftes/starjce. 

SocAef 


3ECTION  AT 


ELLVAT/OA/ 
O/V  A.B. 


FIG.  127.— DETAIL  OF  SHIP  BUFFER,  ALMIRANTE  WHARF. 

The  mechanical  equipment  consisted  of  a  stone  crusher,  a  %-yard  rotary 
mixer  with  hoist,  a  floating  pile  driver  with  a  No.  3,  4,5oo-pound  steam  pile 
hammer,  6  charging  carts,  an  improvised  machine  for  bending  the  rods  cold, 
and  a  number  of  narrow  gauge  cars  on  which  the  shells  were  made. 

The  wharf  was  designed  by  Mr.  T.  Howard  Barnes  with  Mr.  J.  R.  Worces- 
ter as  consulting  engineer,  and  was  constructed  under  his  supervision  in  the 
fall  of  1907  and  the  winter  of  1908,  with  Mr.  Chester  S.  Allen  as  resident 
engineer  and  Mr.  Robert  V.  O'Brien  as  superintendent  for  the  United  Fruit 
Company. 


166 


CHAPTER   XIV. 


TUNNELS  AND   TUNNEL  LINING. 

One  of  the  most  common  uses  of  both  plain  and  reinforced  concrete  is  in 
the  construction  of  tunnels  and  subways.  The  term  tunnel  as  generally  un- 
derstood by  railroad  engineers  is  applied  to  construction  under  cover,  in  which 
the  tunnel  bore  is  advanced  by  drifting,  the  surface  of  the  ground  above  the 
work  not  being  disturbed.  The  term  subways  is  applied  to  open  cut  construc- 


FIG.  128.— ILLINOIS  TELEPHONE  AND  TELEGRAPH  TUNNEL,  CHICAGO,  ILL. 

tion.  A  tunnel  for  heavy  and  fast  railroad  traffic  should  be  built  with  the 
entire  lining,  and  for  still  greater  economy  with  the  roadbed  of  concrete. 
The  old  Bergen  Hill  tunnel  on  the  Lackawanna  Railroad  is  lined  with  brick 
for  a  portion  of  its  length,  yet  fourteen  men  are  at  work  every  night  in  the 
year  inspecting  the  lining  and  repairing  the  track.  This  expensive  and  dan- 
gerous maintenance  work,  which  costs  annually  approximately  $6,000,  is  prac- 

167 


tically  eliminated  in  the  new  tunnel  described  on  page  173,  which  is  built  with 
the  entire  lining  and  roadbed  of  concrete. 

The  standard  tunnel  sections  of  the  New  York  Central  and  Hudson  River 
Railroad  described  below  and  illustrated  by  the  drawings  in  Figs.  129,  130,  131, 
J32>  J33»  show  the  methods  of  construction  employed  in  building  tunnels 
through  the  different  kinds  of  material  encountered  in  this  class  of  work. 

At  the  end  of  the  book  are  shown  photographs  of  a  number  of  representa- 
tive types  of  tunnels  constructed  by  various  railroads  throughout  the  country. 


Packed  w/fh  spa/te 


Quantities    per  L/r?ea/  foof 

/tern 

Unit 

Quantify 

Excavation 
Ho  o  f  Masonry 

Cu.J/ck>. 
Cu.JJds. 

26.493 
2.232 

FIG.  129.— STANDARD  TUNNEL,  N.  Y.  C.  &  H.  R.  R.  R.,  TYPE  B,  SOLID  ROCK,  FIRM  SIDES  AND  ROOF, 

DANGER  FUTURE  FALLS. 

STANDARD  TUNNEL  SECTIONS,  N.  Y.  C.  &  H.  R.  R.  R.— Type  B, 
Fig.  129  shows  a  cross  section  of  the  standard  tunnel  designed  to  meet  the 
condition  of  solid  rock  with  firm  sides  and  roof  but  with  danger  from  future 


1 68 


falls.  The  lining  for  the  arch  is  22  inches  thick  and  is  composed  of  plain  con- 
crete mixed  in  the  proportions  of  i  part  Portland  cement  to  2  parts  of  sand  to 
4  parts  of  broken  stone.  While  the  distance  given  between  the  tracks  is  12 
feet,  this  may  be  increased  to  13  feet  without  changing  the  width  of  the  tunnel. 
Vitrified  pipe,  whose  size  depends  upon  the  length  and  amount  of  water  to  be 
carried  off,  is  laid  in  the  drain  with  open  joints. 


White  Oak  Ribs 
Packed  w/th 
4-in. 


Quanf/t/es  per  L/ffecr/  foot             j 

/fern 

Un/'f 

Qi/ctnf/t_y 

Excavation 
Hoof  Masonry 
^Timbering 

Cu.JJds. 
Cu.J/ct^. 
Ft.  B.M. 

2S.433 
3.233 
306. 

* Based  on  Rib  spacing  of  5/J.CtoC 

F  G.  130.— STANDARD  TUNNEL,  N.  Y.  C.  &  H.  R.  R.  R.,  TYPE  C,  SOLID  ROCK,  YIELDING  ROOF,   FIRM  SIDES. 


Type  C,  Fig.  130,  shows  a  cross  section  of  the  tunnel  where  the  lining  is 
through  solid  rock  and  the  tunnel  is  designed  with  firm  sides  and  yielding 
roof.  The  concrete  lining  for  the  arch  is  22  inches  thick  and  is  mixed  in  the 
proportions  of  1:2:4.  The  12  by  1 2-inch  oak  ribs  carrying  the  4  by  8-inch 

169 


lagging  are  spaced  5  feet  center  to  center.     The  quantities  per  lineal  foot  are 
given  in  tabulated  form  in  Fig.  130. 


PacAecf  w/th  ^ 


may 

Cross  drain  connected  w/th 
Weepho/e$  as  required  by  /oca/  conditions 


Quant/ties  per  lineal  Foot 

Item 

Unit 

Quanf/ty 

£xca  vat  /on 
Arch  Masonry 
Side  Hall 

Cu.J/ds. 
Cu.J/c/*. 
Cu.JJd*. 

/S.S37 
1.355 
3.085 

FIG.  131.— STANDARD  TUNNEL,  N.  Y.  C.  &  H.R.  R.R.,  TYPE  D,  FIRM  BUT  NOT  SELF-SUSTAINING  MATERIAL. 

Type  D,  Fig.  131,  is  a  cross  section  of  a  tunnel  through  firm  but  not  self- 
sustaining  material.  The  lining  is  composed  of  1 13 :6  concrete.  Every  200 
feet,  staggered  on  each  side  of  the  tunnel,  are  placed  refuge  niches  as  shown 


170 


in  Fig.  131.  These  niches  are  7  feet  high  and  3  feet  wide,  with  semicircular 
tops.  All  exposed  corners  and  edges  are  rounded  to  a  i-inch  radius.  While 
the  section  given  in  Fig.  131  is  for  a  single  track  the  same  methods  of  construc- 
tion and  general  clearance  distances  apply  to  double  track  construction. 

White  Oak  Hibs 
Packed  with 
4 in.  Lagging 


4-in.* 


Cross  drain    connecting  weep  holes 

as  required  by  /oca/  conditions 


Quantities  per  Lineal  Foot 

/tern 

Unit 

Quant/ty 

Excavation 
Arch  Masonry 
6/de  Wa//  « 
*T  inhering 

(Zu.JJds. 
ft.  BM 

33.566 

«3.00J 

2.547 

42.5. 

*Ba>sec(  on  Hib   Spacing  of  <5ft.  CtoC 

FIG.  132.— STANDARD  TUNNEL,  N.  Y.  C.  &  H.  R.  R.  R.,  TYPE  E,  YIELDING  MATERIAL. 

Type  E,  Fig.  132,  shows  a  cross  section  designed  to  meet  the  condition  of 
yielding  material.  The  concrete  lining  is  mixed  in  the  proportion  of  i  :2 14 
and  is  provided  with  refuge  niches  similar  to  those  described  in  Type  D. 


171 


172 


The  12  by  1 2-inch  white  oak  ribs  carrying  the  lagging  are  spaced  5  feet  on 
centers.     The  quantities  per  lineal  foot  are  tabulated  in  Fig.  132. 


C/ ass  A  Concrete  /'2:4- 


FIG.  134.— STANDARD  DOUBLE-TRACK  TUNNEL  FACADE,  N.  Y.  C.  &  H.  R.  R.  R. 

STANDARD  TUNNEL  FACADE.— The  standard  facade  for  the  differ- 
ent types  of  tunnels  described  above  is  shown  in  Fig.  134.  With  the  exception 
of  the  arch  ring,  which  is  of  scabbled  granite,  the  entire  facade  is  of  concrete 
mixed  in  the  proportions  of  1 13 :6  for  the  main  body  and  of  i  :2 14  for  the 
coping. 


NEW  BERGEN  HILL  TUNNEL,  D.,  L.  &  W.  R.  R.— As  will  be  seen 
from  the  cross  section  in  Fig.  135,  this  tunnel  is  30  feet  wide  in  the  clear,  23 
feet  5  inches  high  from  the  base  of  the  rail  to  the  crown  of  the  roof  arch,  and 
has  a  concrete  lining  of  a  minimum  thickness  of  two  feet.  The  length  of  the 
tunnel  is  4,280  feet  and  at  two  points  located  at  about  one-third  the  length 
of  the  tunnel  from  each  portal  it  is  connected  to  the  old  tunnel,  which  is  im- 
mediately alongside  the  new  one,  by  an  open  cut  extending  across  the  four 
tracks,  100  feet  long  and  80  feet  wide. 

At  about  the  center  of  each  of  the  sections,  into  which  these  open  cuts 
divide  the  tunnel,  shafts  10  feet  long  and  30  feet  wide  were  sunk  to  the  new 
tunnel.  These  shafts  and  open  cuts  were  used  to  good  advantage  in  moving 
the  waste  material  from  the  headings  and  they  also  greatly  facilitated  the 
work  of  placing  the  concrete  lining. 


The  concrete,  which  vvas  mixed  in  the  proportions  of  1:2^:5,  was  placed 
so  as  not  to  require  tamping  and  was  carefully  spaded  from  the  face  of  the 
forms  which  were  lined  with  No.  20  gauge  sheet  steel  well  greased.  This 
resulted  in  giving  the  exposed  surface  of  the  concrete  a  smooth  metallic  ap- 
pearance which  required  no  further  finishing. 


8//?.x8//?.  Vertical  Drain 
ab'f.  even/  50 Ft. 
SECTfON  AT  MANHOLE  TYP/CAL  SECT/ ON 

FIG.  135.— CROSS  SECTION,  NEW  BERGEN  HILL  TUNNEL. 

The  development  of  the  portals  is  shown  by  the  photograph  in  Fig.  133, 
and  the  roadbed  construction  is  described  in  detail  on  page  178,  Chapter  XV. 

The  tunnel  was  designed  and  built,  during  years  1906  to  1908,  under  the 
direction  of  the  engineering  department  of  the  Delaware,  Lackawanna  and 
Western  Railroad,  Mr.  Lincoln  Bush,  chief  engineer,  and  the  lining  was  put 
in  by  Arthur  McMullen  &  Company,  contractors,  New  York. 


CHAPTER  XV. 

CONCRETE  TIES  AND  ROADBEDS. 

TIES. 

One  of  the  most  serious  and  perplexing  questions  which  confronts  the 
railroad  engineer  of  to-day  is  the  tie  problem.  As  an  evidence  of  this,  during 
the  year  1907  the  railroads  of  the  United  States  used  approximately  118,000,- 
ooo  ties,  a  very  large  percentage  of  which  were  renewals. 


FIG.  136.— CONCRETE^TIESiONkINTERNATIONAL  RYM  BUFFALO. 

This  vast  inroad  upon  the  limited  and  rapidly  decreasing  supply  of  timber 
has  caused  wooden  ties  to  become  poor  in  quality  and  high  in  price,  with  a 
result  that  railroad  engineers  realize  the  necessity  of  procuring  a  substitute 
and  have  been  experimenting  with  concrete  ties  of  various  designs  for  the 
past  few  years.  While  none  of  these  ties  have  been  tested  long  enough  under 
heavy  and  high  speed  traffic  to  warrant  selecting  any  one  as  a  proper  substi- 
tute for  the  wooden  ties  under  all  conditions,  the  success  of  some  of  the  ties 


175 


tested  thus  far  has  been  great  enough  to  convince  railroad  engineers  who  have 
given  the  most  study  to  the  subject  that  a  properly  reinforced  concrete 
tie  with  proper  fastenings  is  a  practical  and  economical  tie,  at  least  for 
tracks  where  the  speed  is  low  and  where  conditions  are  adverse  to  the 
life  of  wood  or  metal.  There  is  no  question  but  what  concrete  ties  are  en- 
tirely suitable  and  economical  for  use  in  yards  and  sidings  and  that  there  is 
an  enormous  place  for  their  introduction  into  this  field  alone. 

Concrete  ties  possess  certain  natural  advantages  over  either  timber  or  steel 
inasmuch  as  dampness,  drawn  fires  and  insects  have  absolutely  no  effect  upon 
them.  In  addition,  they  are  practically  independent  of  the  steel  and  timber 
market,  and  can  be  made  along  the  line  of  the  railroad,  and,  as  compared  with 
the  chemically  treated  timber  or  the  steel  tie,  at  a  reasonable  cost. 

Concrete  ties  have  been  in  successful  use  in  Indo-China,  where  a  very 
peculiar  species  of  ant  destroys  wooden  ties  in  a  few  months,  for  about  ten 
years.  At  the  present  time  it  is  estimated  that  there  are  over  1,000,000  of 
these  ties  in  service.  They  are  of  an  inverted  T-section,  the  flange  of  which 
is  laid  on  the  ground,  the  stem  being  vertical.  The  rails  are  fastened  by  bolts 
which  are  imbedded  in  an  enlargement  of  the  stem  where  the  rails  pass.  In 
Italy  concrete  ties  have  been  tried  with  such  success  that  the  Italian  govern- 
ment has  recently  placed  an  order  with  various  manufacturers  in  Italy  for 
300,000  concrete  ties. 

In  the  design  of  a  successful  tie  there  are  a  number  of  important  functions 
that  seem  to  be  more  or  less  overlooked  in  many  of  the  ties  thus  far  built. 

Cushion  blocks,  if  used,  should  be  removable,  and  the  fastenings  be  of  such 
a  nature  that  they  will  neither  have  a  tendency  to  shake  loose  nor  be  inacces- 
sible, and  may  be  renewed  if  injured. 

Inasmuch  as  automatic  block  signalling  is  being  extended  very  rapidly 
upon  practically  all  of  the  railroads,  it  is  important  that  the  rails  should  be 
insulated,  and  therefore  it  is  necessary  to  place  sufficient  concrete  between  the 
metal  in  contact  with  the  rails  and  the  longitudinal  reinforcement. 

Many  long  ties  have  failed  from  the  fact  that  they  were  not  designed  to 
act  as  cantilever  beams,  thus  being  unable  to  withstand  the  severe  shocks 
coupled  with  the  sinking  of  the  tie  under  passing  loads  on  center  bound  track. 
The  difficulty  experienced  with  tie  blocks  has  been  in  keeping  them  in  longi- 
tudinal position  and  maintaining  them  so  that  the  vertical  deflection  of  one 
rail  will  not  greatly  exceed  that  of  the  other,  thereby  causing  rolling  and 
pounding  of  the  equipment. 

Finally,  ties  should  be  of  sufficient  strength  to  support  derailed  cars 
and  engines  until  they  are  off  the  ends  of  the  ties  and  actually  into  the  ditch ; 
otherwise,  an  ordinary  derailment  may  become  a  serious  wreck. 

177 


CONCRETE   ROADBEDS. 

While  the  original  cost  of  a  solid  concrete  roadbed  is  greater  than  the 
ordinary  cross-tie  construction,  it  is  undoubtedly  more  economical  in  the  end 
for  tunnels  and  subways;  especially  so  where  space  is  cramped,  traffic  heavy, 
and  a  track  cannot  be  temporarily  abandoned,  and  where  with  the  running 


FIG.  138.—  EXPERIMENTAL  CONCRETE  ROADBED,  N.  Y.  C.  &  H.  R.  R.  R. 


rails,  guard  rails  and  third  rails  attached  to  the  long  ties — as  in  the  case  of 
electrified  lines — it  is  extremely  difficult  and  very  expensive  to  maintain  and 
tamp  up  track  to  surface  and  make  tie  renewals. 

Also,  it  can  be  used  to  great  advantage  and  economy  in  rock  and  earth 
cuts  where  there  is  always  a  large  maintenance  expense  to  keep  ditches  open 
and  track  in  good  surface. 

In  addition  to  the  question  of  ultimate  economy,  the  solid  concrete  road- 
bed is  especially  commendable  for  tunnel  and  subway  construction  from  a 
hygienic  standpoint;  for  in  most  tunnels  and  subways  ventilation  is  difficult 
and  the  accumulation  of  grease,  dirt  and  debris,  which  is  readily  held  by  the 
ballast  of  the  cross-tie  track  construction,  is  a  serious  menace  to  the  health 
of  the  passengers.  This  can  be  eliminated  in  the  solid  concrete  construction 

178 


179 


as  the  entire  roadbed  can  be  flushed  with  water  and  kept  in  a  neat,  clean  and 
sanitary  condition. 

ROADBED  CONSTRUCTION  OF  THE  NEW  BERGEN  HILL  TUN- 
NEL, D.,  L.  &  W.  R.  R. — The  drawings  in  Fig.  140  show  the  essential  features 


IFf./0"CtoC 


/x/5  \\ftocfe 


E LEV  AT/ ON 

n  n n 


SECTION 

Guard 
*7"Lag  Screws 

%xll"Lqg  vScAe/Ks- 
5*16" Anchor  Bolts 


u  u 

PLAN 

FIG.  140.— CONCRETE  ROADBED,  NEW  BERGEN  HILL  TUNNEL. 

of  design  and  construction,  while  the  photograph  in  Fig.  139,  which  is  a  view 
taken  at  one  of  the  two  open  shafts  in  the  interior  of  the  tunnel,  shows  the 
finished  roadbed. 

This  construction  consists  of  a  roadbed  of  concrete  laid  on  the  rock  bot- 
tom of  the  tunnel  with  8  in.  by  8  in.  creosoted  timber  tie  blocks  2  feet  6  inches 
long  set  in  the  concrete  and  spaced  i  foot  10  inches  apart  on  centers  for  sup- 
porting the  rails.  These  tie  blocks  leave  a  notch  at  the  outer  end  to  form  a 
shoulder,  and  are  set  in  the  concrete  when  it  is  built.  The  concrete  fills  the 
space  made  by  the  notch  in  the  tie  block,  and  prevents  the  lateral  shifting  of 
the  block  and  railroad  rail,  which  is  attached  to  it  by  lag  screws  and  wrought 
iron  clips.  A  tapered  creosoted  wedge  block  holds  the  tie  block  tight  against 


1 80 


the  concrete,  and  can  be  driven  in  to  take  up  any  looseness  due  to  shrinkage 
or  wear.  The  wedge  is  held  in  place  by  a  lag  screw  extending  about  2  inches 
into  it  through  the  guard  rail.  As  will  be  seen  from  the  drawings,  the  guard 
rail  is  fastened  to  the  tie  blocks  by  lag  screws,  and  is  also  anchored  to  the 
concrete  by  anchor  bolts. 

To  replace  the  tie  blocks,  the  lag  screws  are  removed,  the  wedge  with- 
drawn, the  tie  block  moved  forward  until  the  shoulder  of  the  block  clears  the 


FIG.  141.— BRIDGE  WITH  CONCRETE  FLOOR,  ILL.  CENTRAL  R.  R. 

shoulder  in  the  concrete,  and  the  tie  block  is  then  pulled  out  laterally  without 
disturbing  the  adjacent  tie  blocks  or  rail  fastenings  and  without  raising  the 
rail,  thus  not  interfering  with  traffic. 

One  man  can  replace  these  tie  blocks  and  wedges,  while  with  the  ordinary 
type  of  ballast  track  construction  it  is  necessary  for  a  gang  of  men  to  dig  out 
the  ballast  in  order  to  replace  a  tie,  and  it  also  is  necessary  to  protect  traffic 
while  the  work  is  being  done. 

The  proportions  used  in  the  track  superstructure  were  one  part  of  cement 
to  6  parts  of  Cowe  Bay  gravel  and  sand,  and  in  the  sub-base  the  proportions 
were  i  part  of  cement  to  12  parts  of  crushed  stone  and  sand  for  bringing  the 
sub-base  up  to  proper  level. 

181 


The  table  on  page  183  gives  an  estimated  cost  of  the  ballasted  roadbed  con- 
struction for  double  track.  So  far  as  the  amount  of  tunnel  excavations  and 
the  cleaning  up  of  muck  under  the  roadbed  are  concerned,  the  cost  would  be 
the  same  whether  ballasted  track  or  concrete  roadbed  were  used,  but  with  the 
concrete  roadbed  the  tile  drains  and  trenching  for  ditches  for  the  drains  are 
eliminated.  The  estimated  total  cost,  including  the  conduits,  tile  drains,  creo- 
soted  ties,  etc.,  as  detailed,  for  the  ballasted  double  track,  for  a  length  of  4,280 
feet  amounts  to  $62,568.87,  which  would  be  at  the  rate  of  $14.62  per  lineal  foot 
of  double  track.  If  the  conduit  construction  is  eliminated  from  consideration, 
the  total  cost  amounts  to  $43,429.87,  or  $10.15  per  lineal  foot  of  double  track. 

On  page  184  is  given  a  detailed  statement  of  the  actual  cost  of  the  concrete 
roadbed  construction,  which  does  not  include  any  estimate  for  the  concrete 
sub-base  under  the  finished  track  superstructure.  The  statement  in  detail 
shows  the  actual  cost  for  4,280  lineal  feet  of  double  track  as  taken  from  the 
company's  invoices  and  records.  It  will  be  noted  that  this  statement  includes 
the  two  lines  of  i2-hole  conduits. 

The  railroad  furnished  sand,  stone  and  cement  for  the  concrete  work,  and 
the  price  of  $6.25  per  cubic  yard  given  in  the  detailed  statement  for  concrete 
roadbed  includes  the  contractor's  price,  plus  the  cost  of  material.  The  con- 
tract provided  that  the  contractor  would  lay  the  conduits,  the  railroad  com- 
pany to  furnish  the  material  and  the  contractor  to  receive  the  same  price  per 
cubic  yard  for  the  work  as  he  received  for  the  balance  of  the  concrete  work, 
for  tunnel  lining,  namely  $3.50  per  cubic  yard.  This  price  of  $3.50  per  cubic 
yard  included  everything  excepting  sand,  stone  and  cement.  The  company  as- 
sembled the  tie  blocks  and  rail  and  the  cost  of  these  items  is  included  in  the  de- 
tailed statement.  The  cost  thus  figures  $14.26  per  lineal  foot  of  double  track. 
Eliminating  the  conduit  construction  from  consideration,  the  cost  per  foot  of 
double  track  for  concrete  roadbed  amounts  to  $13.18  per  lineal  foot  of  double 
track  as  against  $10.15  per  lineal  foot  of  ballasted  double  track.  Had  the  con- 
duits been  eliminated  from  the  concrete  roadbed  construction,  the  superstruc- 
ture could  have  been  made  about  4  inches  less  in  height,  which  quantity  would 
have  practically  made  up  for  the  area  of  concrete  occupied  by  the  conduits. 

So  far  as  the  maintenance  cost  is  concerned,  the  concrete  roadbed  construc- 
tion has  resolved  itself  into  a  question  of  simply  track  inspection,  and 
one  inspector  during  the  night  and  one  during  the  day  is  all  that  is  neces- 
sary. When  a  tie  block  must  be  renewed,  it  can  be  done  without  disturbing 
in  any  way  the  rail  fastenings  to  the  tie  blocks  on  either  side  of  the  one  to  be 
renewed,  and  no  removal  of  rail  will  be  necessary.  One  man  can  readily  replace 
a  tie  block  8  inches  by  8  inches  by  2  feet  6  inches,  and  no  interference  whatever 
would  occur  with  traffic  during  such  renewal,  as  an  inch  board  could  be  placed 
underneath  the  rail  on  top  of  the  concrete,  either  side  of  the  block  to  be  re- 
newed, for  temporary  support. 

182 


Still  another  detailed  statement  is  given  below  showing  the  actual  cost  to 
the  company  per  annum  to  maintain  ballasted  track  in  the  present  old  Bergen 
Hill  Tunnel,  which  is  of  the  same  length  as  the  new  tunnel,  the  traffic  through 
it  being  very  heavy.  Capitalizing  the  investment  for  ballasted  track  construc- 
tion and  for  concrete  roadbed  construction  (includng  conduits)  at  4  per  cent, 
and  taking  into  consideration  the  difference  in  cost  of  maintaining,  shows  from 
these  figures  that  the  saving  per  annum  in  cost  per  mile  of  double  track  (with 
conduits)  amounts  to  $7,107.32,  and  without  conduits  the  saving  per  annum 
per  mile  of  double  track  concrete  roadbed  would  be  $6,389.42. 

ESTIMATED  COST  OF  BALLASTED  TRACK  CONSTRUCTION  FOR 

DOUBLE  TRACK  THROUGH  NEW  BERGEN  HILL  TUNNEL 

OF  THE  DELAWARE,  LACKA WANNA  &  WESTERN 

R.  R.  AT  JERSEY  CITY,  N.  J. 

Length  of  tunnel — 4,280  feet. 

232  Gross  tons  gi-lb.  special  open  hearth  rail,  @  $34.00  $7,888.00 

520  Pairs  of  angle  bars  @  1.07  556.40 

3120  Spliced  bolts  @  .03  1/3  104.00 

3120  Nut  locks  @  .009  28.08 

8835  Tie  plates,  6"  X  Y*    X  9"  @  -131  L 157-38 

520  Joint  tie  plates,  6"  X  ^2"  X  n"  @  -171  88.92 
18710  Spikes  @  .0134  327.40 
4677  Creosoted  Y.  P.  ties,  7"  X  9"  X  8  ft.  6"  @  2.10  9,821.70 
6737  Cu.  yd.  stone  ballast,  delivered  @  i.oo  6,737.00 
17976  Lin.  ft.  of  vitrified  6-hole  conduits,  5%  al- 
lowed for  breakage  @  .225  4,044.60 
5720  Yd.  drilling  for  wrapping  conduit  joints  @  .095  543-4° 
2035  Cu.  yd.  rock  excavation  for  tile  drains  @  7.00  14,245.00 
8988  Lin.  ft.  8"drain  tile,  5%  added  for  breakage  @  .085  763.97 
2000  Cu.  yd.  of  extra  concrete  for  conduits  @  6.25  12,500.00 
8560  Lin.  ft.  single  track  laying  and  surfacing  @  .20  1,712.00 

586  Cu.  yd.  concrete  voids  occupied  by  conduit  @  3.50  2,051.00 


$62,568.87 


$62,568.87    4280  —  $14.62  per  foot  of  double  track. 

If  conduits  are  eliminated  from  consideration,  cost  would  be  $43,429.87. 

$43,429.87  -j-  4280=:  $10.15  per  foot  of  double  track. 

183 


DETAILS    OF    ACTUAL    COST    OF    CONCRETE    ROADBED    CON- 

STRUCTION  FOR  DOUBLE  TRACK  THROUGH  NEW  BERGEN 

HILL    TUNNEL     OF    THE     DELAWARE,     LACKAWANNA 

AND  WESTERN  RAILROAD  AT  JERSEY  CITY,  N.  J. 

Estimate  includes  electric  wire  conduits.     Length  of  tunnel,  4280  feet. 
232      Gross  tons  gi-lb.  special  open  hearth  rail,  $34.00       $7,888.00 


520      Pairs  of  angle  bars, 
3120      Splice  bolts 
3120      Nut  locks, 
8835     Tie  plates,  6"  X  V*    X  9", 

520      Joint  tie  plates,  6"  X  %"  X  "", 
17976      Lin.  ft.  vitrified  6-hole  conduit,   5%   allowed  for 

breakage, 

5720      Yd.  drilling  for  wrapping  conduit  joints, 
9360     Creosoted  yellow  pine  tie  blocks,  8"  X  8"  X  2  ft.  6," 
9360      Creosoted  yellow  pine  wedges,  2j4"  X  8"  X  2  ft.  6" 
17680      Intermediate  rail  clips, 
18720      Pieces  round  iron  i"  X  15"  for  reinforcement, 

1040     Joint  rail  clips, 
18720      Lag  screwspike,  7/s"  X  7/4", 
9360      Lag  screws  for  guard  rail,  ^4"  X  n", 
9360      Washers  for  guard  rail,  %"  X  3", 
9360     Wedge  lag  screws,  %"  X  7", 
18555      Lin.  ft.  of  Y.  P.  creosoted  guard  rail,  5"  X  8", 
4680      Guard  rail  anchor  bolts,  %"  X  18", 
4680     Guard  rail  washers,  */%"  X  3", 
4680     Anchor  nuts,  2%"  sq.  X  i/4"  thick, 
4680      Paraffine  tubes  for  anchor  bolts, 
3754.4  Cu.  yd.  concrete, 
1019.2  Cu.   yd.   concrete   voids   occupied   by   tie   blocks, 

wedges  and  conduits, 

Labor  and  engineering  for  assembling  and  fast- 
ening complete,  the  tie  blocks,  wedges,  guard 
rail,  rail,  rail  joints,  screws,  spikes,  etc.,  8560 
lin  ft., 


1.07 

•03  i 
.009 

•131 
.171 

.225 

•095 
45-00 
45-00 

•039 


556.40 

104.00 

28.08 

1,157-38 
88.92 

4,044.60 

543.40 
5,616.00 
i,579.5o 

689.52 


.06  1/3  1,185.60 


.051 
.046 
.034 
•03 
.013 
45-00 
.08  2/3 

.03 
.08 
.005 
6.25 


53-04 
861.12 
318.24 
280.80 
121.68 

2,783.25 
405.60 
140.40 
374.40 
23-40 
23,465.00 


3-5°    3,567.20 


.60    5,136.00 


$61,011.53 
$61,011.53  —  4280  =  $14.26  per  linear  foot  of  double  track  with  conduits  and 

wrapping. 

$56,423.53,  total  cost,  exclusive  of  conduits. 
$56,423.53  —  4280  =  $13.18  per  linear  foot  of  double  track. 


184 


COST  PER  ANNUM          BALLASTED  TRACK  (With  Conduits) 

$62,568.87,  @  4% $2,502.75 

Track  maintenance, 

$565.00  per  mo.  X  12 6.780.00 


Length  of  4280  ft $9,282.75 

5280 

$9,282.75    X $11,451.57  per  mile 

4280 

COST  PER  ANNUM           BALLASTED  TRACK  (Without  conduits) 

$43,429.87,  @  4% $1,737.19 

Track  maintenance, 

$565.00  per  mo.  X  12    6,780.00 


Length  of  4280  ft $8,517.19 

5280 

$8,517.19   X , $10,507.20  per  mile 

4280 

COST  PER  ANNUM  CONCRETE  ROADBED       (Without  Conduits) 

$61,011.53,   @  4% $2,440.46 

Track  maintenance, 

$90.00  per  mo.  X  12 1,080.00 


Length  of  4280  ft $3.520.46 

5280 

$3,520.46  X  $4,344.25  per  mile 

4280 

COST  PER  ANNUM  CONCRETE  ROADBED        (Without  conduits) 

$56,423.53,  @  4% $2,256.94 

Track  maintenance, 

$90.00  per  mo.  X  12   1,080.00 


Length  of  4280  ft $3*336.94 

5280 

$3»336.94  X $4,117.78  per  mile 

4280 

This  roadbed  construction  was  designed  and  patented  by  Mr.  Lincoln 
Bush,  who  was  at  the  time  Chief  Engineer  of  the  Delaware,  Lackawanna  and 
Western  Railroad. 

185 


w 


186 


CHAPTER  XVI. 

TELEGRAPH  POLES,  POWER  TRANSMISSION  POLES  AND 

TOWERS. 

TELEGRAPH  POLES. 

Owing  to  the  increasing  scarcity  and  inferior  quality  of  wood,  which  has 
heretofore  been  used  exclusively  for  telegraph  and  trolley  poles,  engineers 


FIG.  143.— CONCRETE  TELEGRAPH  POLES,  P.,  L.  W.  OF  P. 

have  been  experimenting  with  reinforced  concrete  for  a  number  of  years  with 
the  result  that  poles  have  been  designed  which  are  meeting  the  requirements 
in  every  way. 

Among  the  advantages  of  the  reinforcd  concrete  pole,  the  facts  are 
that  lines  thus  equipped  have  practically  no  trouble  from  lightning,  the  rein- 
forcing rods  apparently  acting  as  conductors  of  electricity;  that  the  pole  re- 
quires no  preservative  or  paint  to  protect  it  from  the  ravages  of  weather,  as  is 
the  case  with  wood  or  steel;  and  that  it  is  elastic  enough  to  withstand  all 
ordinary  shocks. 

187 


That  a  reinforced  concrete  pole  of  economical  dimensions  possesses  the 
requisite  strength  has  been  demonstrated  both  in  this  country  and  abroad  by 
experiments*  on  concrete  and  wooden  poles  of  the  same  sizes. 

In  1907  Mr.  Robert  A.  Cummingsf  made  some  comprehensive  tests  for  the 
Pennsylvania  lines  west  of  Pittsburg  on  reinforced  concrete  and  white  cedar 
poles,  which  resulted  in  showing  that  the  concrete  pole  was  not  only  stronger 
than  the  wooden  poles  but  also  that,  after  breaking,  the  end  was  held  in  a 


ELEVAT/0/V  S£CT/0/V    AT 

FIG.  144.— CONCRETE  TELEGRAPH  POLES,  P.,  L.  W.  OF  P. 

*Cement  Age,  August,  1907,  p.  84;  Cement,  July,  1903,  p.  168;  Concrete,  March,  1907, 
P   40. 

t  Cement  Age,  August,  1907,  p.  84. 

1 88 


slightly  inclined  position  by  the  reinforcement,  while  the  wooden  pole  frac- 
tured completely  and  fell  to  the  ground. 

Mr.  W.  W.  Bailey*  made  some  very  thorough  tests  in  1908  of  reinforced 
concrete  and  of  cedar  poles  30  feet  long  and  embedded  5  feet  in  the  ground. 
Both  poles  were  7  inches  at  the  top  and  12  inches  at  the  ground  line.  The 
concrete  pole  was  reinforced  with  four  %-inch  twisted  steel  rods  bound  to- 
gether with  No.  9  binding  wire.  With  a  horizontal  pull  at  the  top  of  1,780 
pounds,  the  concrete  pole  deflected  17  inches  and  broke  from  a  horizontal  pull 
of  7,200  pounds  with  a  deflection  of  over  6  feet  before  falling,  while  the  wooden 


FIG.  145.— TICKLER  POLES,  N.,  C.  &  ST.  L.  RY. 

pole,  with  a  pull  of  1,780  pounds,  deflected  33  inches  and  broke  at  2,200  pounds. 

In  general  concrete  poles  are  designed  with  a  square  section,  with  the  cor- 
ners chamfered  off,  tapering  from  bottom  to  top  and  with  tapering  reinforce- 
ment, thus  meeting  the  condition  of  the  decreasing  strain,  which  is  of  course 
greatest  at  the  ground  line  and  decreases  toward  the  top  where  the  strain  is 
applied.  Aside  from  telegraph  poles  such  as  are  described  below,  concrete  has 
been  used  to  good  advantage  in  the  construction  of  tickler  poles,  a  successful 
type  of  which  is  described  on  page  191. 

*Concrete  Engineering,  March,  1909,  p.  67. 

189 


TELEGRAPH  POLES,  P.,  L.  W.  OF  P.— The  drawing  in  Fig.  144  shows 
the  details  of  poles  designed  by  Mr.  F.  M.  Graham,  Engineer,  Maintenance  of 
Way,  which  the  Pittsburg,  Ft.  Wayne  and  Chicago  division  of  the  Pennsyl- 
vania Railroad  are  installing  along  their  lines.  These  poles  range  in  height 
from  25  to  34  feet  and  are  8  inches  square  at  the  bottom,  tapering  to  6  inches 
square  at  the  top,  with  the  corners  chamfered  two  inches.  The  reinforcement 
consists  of  24  ^-inch  wires  running  the  full  length  of  the  poles.  Holes  are 
left  in  the  poles  for  the  brace  and  cross  arm  bolts  and  also  for  the  climber 
steps.  The  poles  are  built  at  gravel  pits  along  the  line  and  a  wet  mixture  of  i 
cement  to  3  sand  to  3  of  gravel  is  used.  After  the  poles  have  cured,  they  are 
hauled  out  on  cars  to  the  point  of  erection  where  they  are  set  four  feet  in  the 
ground  and  bedded  in  stone  screenings.  The  photograph  in  Fig.  143,  page  187, 
shows  these  poles  in  actual  service. 


s» 
S 

10      $  « 
•  —  ert-o' 

s 

sj 

1 

0 

0 

V 

T 

FIG.  146.— DETAILS  OF  TICKLER  POLE,  N.,  C.  &  ST.  L.  RY. 
IQO 


t  of  4th.  Cross  ft  arm    El  /5OO 


TICKLER  POLES,  N.,  C.  &  St.  L. 

RY. — In  1904  the  Nashville,  Chattanooga 
and  St.  Louis  Railway,  Mr.  Hunter  Mc- 
Donald, Chief  Engineer,  erected  four 
bridge  warnings  using  concrete  poles  for 
supporting  the  warning  straps  or  ticklers 
which  have  given  such  satisfaction  that 
they  have  been  adopted  as  standard  for 
that  purpose.  These  poles,  the  details  of 
which  are  shown  by  the  drawings  in  Fig. 
146,  and  by  the  photographs  in  Fig.  145, 
are  8  inches  square  at  the  bottom  and  6 
inches  square  at  the  top,  and  are  rein- 
forced for  the  full  length  of  29  feet  with 
four  */2-inch  round  rods  banded  every  foot 
with  No.  12  soft  wire.  The  ticklers  on 
two  of  the  poles  are  carried  by  cross-arms 
and  braces  of  concrete  cast  with  the  pole, 
but  since  it  was  found  that  the  concrete 
cross-arms  were  expensive  as  well  as  so 
heavy  as  to  cause  the  pole  to  bend  to  an 
unsightly  extent,  gas  pipe  cross-arms 
were  used  instead  and  found  satisfactory 
in  combination  with  the  concrete  pole. 

POWER  TRANSMISSION  POLES 
AND  TOWERS. 


In  the  long  distance  transmission  of 


Note 

Batter  of  wo/te  3'fo/ft 

Center  of  ro/7s  *" from  electrical  energy  from  one  point  to  an- 
surface  of  concrete  other,  it  is  necessary  from  an  economical 
standpoint  to  use  longer  spans  than  wood- 
en poles  can  safely  carry.  This  condition 
led  first  to  the  adoption  of  steel  structures 
which  not  only  had  the  effect  of  increas- 
ing the  initial  cost  and  cost  of  mainte- 
nance, but  also  necessitated  a  wider  right 
of  way  than  single  pole  construction.  To 
eliminate  these  disadvantages  and  at  the 
same  time  obtain  a  pole  of  sufficient 
strength  for  long  span  construction  engi- 
neers turned  to  reinforce  concrete  with  the 


\  E/  335 


TC.  147.— DETAILS  OF  CONSTRUCTION,  BROWNS- 
VILLE TRANSMISSION  TOWERS. 


191 


result  that  poles  have  been  designed  which  after  several  years  of  trial  are 
proving  entirely  satisfactory. 

In  constructing  concrete  power  transmission  poles,  both  hollow  and  solid 
sections  are  employed.  An  example  of  the  former  type  is  the  Brownsville 
tower  described  below,  while  the  poles  which  the  Lincoln  Electric  Light  and 
Power  Company*  use  to  carry  their  wires  over  the  old  Welland  Canal  at  St. 


FIG.  148.— BROWNSVILLE  TRANSMISSION  TOWERS,  WEST  PENN.  RAILWAYS  CO. 

Catherines,  Ontario,  are  noteworthy  examples  of  the  latter  type.  These  con- 
sist of  reinforced  concrete  poles  150  feet  high,  142  feet  being  above  the  ground. 
They  are  31  inches  square  at  the  base  and  n  inches  square  at  the  top  and  are 
reinforced  with  four  2^-inch  round  rods.  The  poles  were  made  horizon- 
tally on  the  ground  and  raised  into  upright  position  by  means  of  a  pair  of 
shear  legs. 

BROWNSVILLE  TRANSMISSION  TOWERS.— In  the  spring  of  1907 
the  West  Pennsylvania  Railways  Company  was  confronted  with  the  problem 
of  supporting  a  high  potential  power  transmission  line  across  the  Mononga- 
hela  River  at  Brownsville,  Pa.,  a  distance  of  1,014  feet,  and  at  the  same  time 


Transactions  American  Society  Civil  Engineers,  Vol.  LX.,  p.  160. 

192 


of  keeping  the  cable  jgT/2  feet  above  the  low  water  mark,  as  required  at  that 
point  by  government  regulations. 

On  the  Brewnsville  side  of  the  river  no  tower  was  necessary,  as  a  firm 
anchorage  could  be  obtained  in  the  sub-station  of  the  company.  On  the  op- 
posite side,  where  a  tower  was  found  necessary,  it  was  decided  to  build  a  main 
tower,  as  close  to  the  river  as  possible,  designed  to  carry  only  the  weight  of 
the  cables  and  the  wind  pressure  against  the  cables  and  the  tower  itself,  and 
230  feet  back  of  this  a  shorter  tower  designed  to  serve  as  an  anchorage  taking 
the  direct  strain  of  the  main  span. 

In  order  that  the  main  tower,  the  general  details  of  design  and  construction 
of  which  are  shown  by  the  drawings  in  Fig.  147,  might  be  designed  for  practi- 
cally the  wind  stress  alone,  a  special  roller  bearing  saddle  was  devised  for  car- 
rying the  cables  over  the  tower  without  a  rigid  connection.  Both  towers  were 
designed  as  cantilever  beams.  The  wind  pressure  considered  in  connection 
with  the  wind  stress  on  the  cables  was  taken  as  40  pounds  per  square  foot  and 
the  load  on  the  cables  as  20  pounds  per  square  foot  of  projected  ice-coated 
section.  The  cables  themselves  were  treated  as  catenaries,  the  maximum  unit 
load  therefore  being  the  resultant  of  the  weight  of  the  cable  and  the  ice  in  a 
vertical  direction  and  the  wind  load  in  a  horizontal  direction.  With  a  maxi- 
mum allowable  sag  of  36.6  feet  and  a  minimum  sag  of  33.4  feet,  there  is  as- 
sumed to  be  a  pull  of  122,000  pounds  exerted  on  the  anchorage  tower  at  an 
average  height  of  38^  feet  above  its  base. 

The  photograph  in  Fig.  148  shows  both  the  main  and  the  anchorage  towers. 
The  main  tower,  which  rises  115  feet  above  its  foundations,  is  pyramidal  in 
form,  being  8  feet  2  inches  square  at  the  base  and  i  foot  square  at  the  top  and 
has  hollow  walls  i  foot  thick  up  to  a  point  84  feet  above  the  base,  where  the 
section  becomes  solid.  The  anchor  tower,  which  is  of  solid  section  through- 
out, is  4  feet  by  10  feet  at  the  base  and  batters  up  to  a  section  i  foot  square  at 
41  feet  i  inch  above  the  base,  from  which  point  it  is  of  uniform  section  up  to 
the  full  height  of  55  feet. 

In  addition  to  the  vertical  reinforcing  rails  shown  in  Fig.  147,  two  spirals 
each  of  ^4-inch  cable,  were  wound  i  foot  apart,  thus  making  a  2-foot  pitch  for 
each  cable.  Gravel  concrete  mixed  very  wet  was  used  throughout,  the  foot- 
ing being  mixed  in  the  proportions  of  1 12  %  15  and  the  walls  in  the  proportions 
of  1 12%  14. 

Falsework  12  feet  square  was  built  for  both  towers  sufficiently  in  advance 
of  the  wooden  form  so  that  both  the  forms  and  the  3O-ft.  reinforcing  rails 
might  be  raised  into  position.  For  the  exterior  forms,  three  sections  6  feet 
high  were  made  for  each  tower.  One  section  was  filled  each  day,  and  on  the 
third  day  the  bottom  section  was  removed,  cut  down  to  the  proper  section  and 
used  above.  Before  filling  the  form,  each  was  given  a  thin  coat  of  motor 

193 


grease.  The  interior  forms  for  the  main  tower  consisted  of  hemlock  sheath- 
ing backed  up  by  2  by  4  inch  bracing  and  were  left  in  the  tower. 

The  concrete  was  mixed  in  a  No.  i  mixer,  driven  by  a  lo-horse  power  belt 
connected  electric  motor  and  was  hoisted  to  the  required  elevation  by  a  fric- 
tion hoist  operated  by  a  7^2  horse  power  single  phase  motor. 

The  towers  were  designed  and  constructed  by  the  West  Penn.  Railways 
Company  under  the  general  direction  of  Mr.  W.  E.  Moore,  General  Manager, 
and  Mr.  J.  S.  Jenks,  Superintendent  of  Transmission,  with  Mr.  F.  W.  Scheid- 
enhelm,  Structural  Engineer,  in  direct  charge  of  design  and  construction. 


FIG.  149.— CONCRETE  PROTECTION  PIER,  N.  Y.  C.   &  H.  R.  R.  R. 

IQ4 


CHAPTER  XVII. 


POSTS  AND  FENCES. 

The  growing  scarcity  and  the  increasing  cost  of  suitable  timber  for  posts 
has  brought  concrete  into  quite  general  use.  Concrete  posts  possess  the  ad- 
vantage over  wooden  ones  not  only  of  unlimited  life,  greater  strength  and  re- 
sistance to  the  action  of  fire  and  decay,  but  also  they  present  a  more  pleasing 
appearance. 

.As  to  the  adaptability  of  the  concrete  post  to  railroad  use,  the  committee 
appointed  by  the  American  Railway  Engineering  and  Maintenance  of  Way 
Association"  to  investigate  this  subject  reported  to  the  annual  convention  at 
Chicago  in  March,  1909,  in  part  as  follows: 

"From  observation  of  concrete  fence  posts  your  Committee  considers 
that  the  concrete  fence  post  will  heave  very  little  or  not  at  all,  as  posts  set 
from  two  to  five  years  are  at  present  in  almost  perfect  alignment,  and  not 
a  loose  or  broken  post  was  found.  They  appear  sufficiently  strong  for  all 
practical  purposes  after  being  properly  cured  and  set.  The  claim  that 
concrete  posts,  reinforced  with  steel,  form  lightning  protectors  appears 
reasonable.  They  will,  of  course,  resist  the  action  of  fire  and  decay.  They 
will  not  float  and  cannot  be  displaced  so  easily  as  wood  posts.  On  the 
other  hand,  concrete  posts  must  be  carefully  handled  in  loading  and  un- 
loading and  well  cured  before  using.  Fence  wire  in  contact  with  their 
surfaces  should  be  well  galvanized. 

"The  concrete  post  is  much  heavier  than  the  wood  post  and  the  cost 
of  distributing  is  about  25  per  cent  greater. 

"It  would  seem  that  the  concrete  post  is  particularly  adapted  to  rail- 
road use.  Most  of  the  post  machines  are  cheap  and  portable  and  the  ma- 
terials used  are  in  daily  use  on  all  roads  using  concrete.  The  materials 
are  cheap  and  easily  obtained." 

In  regard  to  the  various  types  and  methods  of  making  such  posts  the  same 
committee  after  corresponding  with  over  twenty  manufacturers  of  posts  and 
post-making  machinery  in  the  United  States  and  Canada  reported  that : 

"A  majority  of  these  firms  use  or  advise  the  use  of  Portland  cement 
and  gravel  ranging  from  the  size  of  sand  to  pebbles  which  will  pass  a  wire 


*Bulletin  No.  107,  January,  1909,  p.  323. 

195 


screen  having  meshes  of  from  %  to  i  inch  square.  The  ratio  of  cement 
and  gravel  is  as  i  to  4.  The  methods  of  reinforcing  and  tamping  concrete 
posts  vary  almost  as  much  as  those  of  fastening  the  fence  wire  to  the 
posts.  The  machines  are  of  various  capacities  and  design — from  the  one 
post  hand  mold  to  the  'post  per  minute'  power  machine,  with  continuous 
mixer  attachment.  The  average  total  cubic  contents  of  the  7-foot  post  is 
0.825  cubic  feet,  of  the  8-foot  post,  0.95  cubic  feet.  The  weights  vary  from 
65  pounds  to  95  pounds,  according  to  methods  of  manufacture  and  rein- 
forcement used.  Concrete  posts  retail  for  from  25  cents  to  35  cents  per 
post.  End  and  gate  posts  are  of  about  three  times  the  volume  and  cost 
of  intermediate  posts.  In  section  concrete  posts  vary  from  square  or  rec- 
tangular to  triangular,  half  round  and  circular.  Reinforcements  are  of 
wire,  wood,  strap  steel,  steel  and  wire  truss,  wood  and  wire  truss,  chain 
scrap  strips  and  expanded  metal.  Fence  wire  fastenings  are  also  of  vari- 
ous forms,  from  the  wire  loop  around  the  post  to  the  patent  staple  encase- 
ment. 

"All  the  posts  observed  taper  from  a  smaller  top  to  a  larger  base. 
Some  have  very  wide  concrete  bases." 

FENCE  POSTS.* 

Concrete  fence  posts  are  either  constructed  in  advance  and  put  in  place 
after  they  have  set  sufficiently  hard  as  not  to  be  injured  by  handling  or  are 
moulded  in  place.  The  posts  in  Dellwood  Park  described  on  page  197  are  ex- 
amples of  the  former  type  of  construction,  while  the  posts  along  the  Harlem 
division  of  the  New  York  Central  and  Hudson  River  Railroad,  described  on 
page  197,  exemplify  the  latter.  Fig.  150  is  a  suggested  design  of  forms  for 
fence  posts  when  constructed  in  advance.  As  will  be  seen  from  the  sketch, 
the  posts  are  made  with  every  alternate  post  lying  the  opposite  way,  thus 
making  one  intermediate  board  serve  as  a  side  to  two  posts. 

As  stated  in  the  excerpt  from  the  committee  report  given  above,  there  are 
a  variety  of  means  for  fastening  fence  wire  to  the  post.  Two  methods  are 
illustrated  in  Fig.  150,  one  being  by  embedding  in  the  concrete  a  piece  of  No. 
12  copper  wire,  12  inches  long  bent  in  half  with  the  halves  twisted  together 
and  with  the  ends  projecting  from  the  post  about  two  inches,  to  which  the 
fence  wires  are  connected,  while  the  other  consists  in  leaving  a  hole  in  the 
concrete  through  which  the  fence  wire  can  be  strung.  This  is  done  by  placing 
well  greased  round  rods  or  wood  dowels  in  the  post  forms  at  the  desired  spots 
and  leaving  them  in  the  concrete  about  a  day,  when  they  can  be  readily  re- 
moved. A  very  simple  and  satisfactory  method  is  to  use  large  galvanized 


*Methods  of  making  concrete  posts  are  treated  in  "Concrete  About  the  Home  and 
on  the  Farm,"  published  by  The  Atlas  Portland  Cement  Company. 

196 


staples  having  their  ends  bent  so  as  to  hook  into  the  concrete,  while  still  an- 
other way  is  by  bolting  a  galvanized  iron  strip  to  the  post  as  was  done  in  the 
case  of  the  Dell  wood  Park  posts  described  on  page  197. 

STANDARD  CONCRETE  FENCE  POSTS,  N.  Y.  C.  &  H.  R.  R.  R.— 
Fig.  152  gives  the  details  of  design  and  construction  of  these  posts  while  the 
photograph  in  Fig.  151  shows  the  forms  in  place  preparatory  to  pouring  the 
concrete. 


N$l2.Copper  JV/'re 


FIG.  150.— FORMS  FOR  FENCE  POSTS. 

The  main  posts  are  made  of  1 13  :6  concrete  poured  very  wet,  while  the  foot- 
ings for  the  intermediate  iron  posts  are  mixed  in  the  proportions  of  1 14 :j%. 
The  forms  are  taken  down  12  hours  after  being  filled  and  the  green  concrete 
is  floated  with  water  and  rubbed  with  a  i  :2  cement  and  sand  brick  until  the 
desired  finish  is  attained. 

In  making  these  posts  all  the  material  is  unloaded  from  a  work  train  in 
advance  of  the  job  and  a  gang  of  six  men  do  the  work,  two  men  excavating 
holes,  two  setting  up  the  forms  and  two  mixing  and  placing  the  concrete. 

DELLWOOD  PARK  FENCE  POSTS,  C.  &  J.  RY.— The  posts  shown 
in  detail  by  the  drawings  in  Fig.  154  and  by  the  photograph  in  Fig.  153  were 
built  by  the  Chicago  and  Joilet  Electric  Railway  to  support  the  galvanized 
iron  woven  wire  fencing  which  encloses  its  amusement  resort  at  Dellwood 

197 


FIG.  151.— FORMS  IN  PLACE,  FENCE  POSTS,  N.  Y.  C.  &  H.  R.  R.  R. 

IUn. 


J5Jn.\ 


i  1 1  i  i  i  ii  H  •  i  i  y  y  i  y 


11 


AT  CEMENT  POST 


I  BEAM  POST  DETAILS 

FIG.  152.— CONCRETE  FENCE  POSTS,  N.  Y.  C.  &  H.  R.  R.  R. 
I98 


Park.  They  are  spaced  10  feet  on  centers  and  are  7  and  9  feet  long,  4  inches 
by  6  inches  at  the  bottom  and  4  inches  by  4  inches  at  the  top  and  are  rein- 
forced by  four  *4-inch  corrugated  bars,  one  at  each  corner.  The  wire  fencing 
is  attached  to  them  by  a  %  by  i  inch  galvanized  iron  strip  bolted  to  each  post 
through  holes  cast  in  the  latter  as  it  was  made.  Each  post  was  cast  in  a  sepa- 
rate wooden  mould  laid  flat  on  a  2  by  8  inch  plank,  as  shown  in  Fig.  154,  and 
was  allowed  to  season  at  least  a  month  before  being  set  in  place.  They  were 
made  of  i  part  Atlas  Portland  Cement  to  2  parts  stone  screenings,  ranging 
from  dust  to  ^4-inch  pieces. 


FIG.  153.-  CONCRETE  FENCE  POSTS,  DELLWOOD  PARK. 

The  posts  in  the  corners  and  at  angles  in  the  fence  are  made  of  larger  sec- 
tions than  the  others  and  are  reinforced  with  a  2%  by  2^2  by  *4  inch  angle.  A 
concrete  brace  is  extended  from  each  of  these  posts  to  the  base  of  the  adjoin- 
ing regular  posts  which  are  set  in  concrete,  all  other  posts  being  simply  set  in 
the  ground  and  tamped  around.  Two  men  were  engaged  in  making  these 
posts  and  could  produce  about  forty  a  day  at  an  average  cost  of  65  cents  for 
the  g-foot  posts.  The  price  is  rather  high  owing  to  the  expensive  fittings,  the 
cost  of  materials  and  methods  of  fastening  the  wire  to  post. 


199 


CONCRETE  FENCE  POSTS,  B.  &  O.  R.  R.*— The  Baltimore  and  Ohio 
Railroad  concrete  fence  posts  are  of  uniform  size,  5  by  5  inches,  and  are  rein- 
forced with  four  ^4-inch  rods.  Wires  are  built  into  the  back  of  the  post  pro- 


n-* 


form 

FIG.  154.— DETAILS  OF  CONSTRUCTION,  DELLWOOD  PARK  FENCE  POSTS. 

jecting  four  inches,  to  which  the  woven  wire  fence  is  attached  by  means  of 
pliers.     These  posts  placed  cost  44^  cents  each. 

*Proceedings   Association  of  Railway   Superintendents   of   Bridges   and   Buildings, 
October,  1906,  p.  69. 


200 


MILE  POSTS. 

Fig.  155  shows  a  type  of  concrete  mile  posts  in  use  on  the  lines  of  the  Chi- 
cago and  Eastern  Illinois  Railroad  that  is  meeting  with  success  from  a  stand- 
point both  of  maintenance  and  permanence.  As  will  be  seen  from  the  draw- 
ing the  post  is  8  by  8  inches  square  and  8  feet  long,  with  4  feet  6  inches  above 
ground. 


FIG.  155.— MILE  POSTS,  C.  &  E.  I.  R.  R. 


FIG.  156.— WHISTLE  POSTS,  C.  &  E.  I.  R.  R. 


201 


The  post,  which  weighs  498  pounds,  is  composed  of  concrete  mixed  in  the 
proportions  of  i  part  cement  to  i  part  sand  to  2  parts  crushed  stone  and  is 
reinforced  for  the  entire  length  with  one  i-inch  corrugated  bar  placed  in  the 
center. 

In  moulding  the  posts  the  form  is  laid  with  the  letters  on  the  bottom,  and 
the  sides  are  plastered  with  mortar  to  a  thickness  of  ^2  inch  before  the  ordi- 
nary concrete  is  put  in. 

The  black  face  concrete  of  the  lettered  panel  is  colored  with  *4  pound  of 
lampblack  mixed  with  i  quart  of  cement  in  water,  and  is  separated  from  the 
white  concrete  above  and  below  by  two  recesses  across  the  face  of  the  post. 


WHISTLE  POSTS. 

The  posts  in  Fig.  156  represents  a  typical  concrete  whistle  post  in  use  on 
the  Chicago  and  Eastern  Illinois  Railroad.  Aside  from  the  shape  of  the  cross 
section,  which  is  in  the  form  of  a  T,  the  essential  details  of  construction  are 
the  same  as  for  the  mile-posts  on  the  same  road  described  above.  These  posts 
are  set  at  points  10  feet  to  the  right  of  the  track  center  and  2,000  feet  each  way 
from  highway  crossings. 

The  Lake  Shore  and  Michigan  Southern  Railway  use  concrete  whistle 
posts,  made  in  moulds  like  blocks,  which  are  3^/2  inches  thick,  12  inches  wide 
and  are  set  about  5%  feet  above  the  ground.  The  letters  and  signs  are  cast 
right  in  the  post  and  are  painted  black. 


CLEARANCE  POSTS. 

Fig.  157  shows  the  design  of  concrete  clearance  posts  on  the  Chicago  and 
Eastern  Illinois  Railroad,  which  are  set  between  main  track  and  siding  at  a 
point  where  the  distance  between  centers  is  10  feet.  These  posts  are  6  by  6 
inches  square  and  are  reinforced  for  the  entire  length  with  either  a  54-inch 
scrap  gas  pipe,  a  ^2-inch  corrugated  bar  or  four  No.  9  wires. 


PROPERTY  LINE  POSTS. 

Fig.  158  represents  the  standard  concrete  property  line  posts  which  are  set 
with  the  center  on  the  property  line  and  with  the  letters  facing  the  track. 
These  posts  are  made  in  triangular  section  and  are  reinforced  for  the  entire 
length  with  a  J^-inch  scrap  gas  pipe  or  a  %-inch  corrugated  bar  or  four  No.  9 
wires. 

202 


fs 


I 


CJ 


fc 

Uj 

o 


1; 
§! 


vo 


FIG.  157.— CLEARANCE  POSTS, 
C.   &  E.  I.  R.  R. 


FIG.  158.  —PROPERTY  LINE  POSTS.k 
C.  &  E.  I.  R.  R. 


203 


FENCES. 

In  places  where  a  substantial  fence  is  required  ultimate  economy,  strength, 
durability  and  a  pleasing  appearance  can  be  attained  by  the  use  of  reinforced 
concrete.  Two  types  of  concrete  fences  have  been  tried  with  success,  viz.: 
solid  reinforced  concrete  and  cement  plaster  on  metal  lath. 

The  solid  type  of  fence  generally  consists  of  a  vertical  slab  of  reinforced 
concrete  about  3  inches  thick  with  a  rounded  moulding  like  a  hand  rail  on  the 
upper  horizontal  edge. 


FIG.  159.— FENCE  AT  AVENUE  J,  B.  R.  T.  CO. 


PLATFORM  FENCES. 
An  example  of  the  plaster  type  of  fence  is  described  below: 

PLATFORM  FENCES,  BROOKLYN  RAPID  TRANSIT  CO.— These 
fences,  which  form  guard  railings  on  the  outside  and  ends  of  the  platforms  de- 
scribed on  page  106,  Chapter  VII.,  are  240  feet  long,  4  feet  6  inches  high,  and  2 
inches  thick  and  are  surmounted  by  a  railing  45/3  inches  high  and  5  inches  wide. 
The  drawings  in  Fig.  160  show  the  essential  details  of  design  and  construction 
while  the  photograph  in  Fig.  159  shows  the  fence  at  Avenue  J  Station. 

204 


The  reinforcement  consists  of  metal  lath  of  No.  28  gauge  and  is 
carried  in  continuous  sheets  through  the  entire  length  of  the  fence,  except  at 
expansion  joints.  The  posts,  which  are  10  feet  on  centers,  are  reinforced  with 
four  ^/2-inch  rods  set  deep  in  the  concrete  platform  and  the  railing  has  two 
94-inch  rods  running  longitudinally  with  a  strip  of  lath  laid  horizontally.  The 
posts  are  formed  by  two  short  pieces  of  lath  put  in  the  shape  of  channels  and 
placed  around  the  reinforcing  rods,  one  channel  being  on  each  side  of  the  re- 
inforced sheet  of  the  panels. 


<5£Cr/OM  A-A  ELEI/AT/ON  6ECT/O/V  B-B 

FIG.  160. ^DETAILS  OF  CONSTRUCTION,  PLATFORM  FENCE,  B.  R.  T.  CO. 


205 


In  constructing  the  fences  the  lath  was  held  in  place  by  i-inch  angle  stud- 
ding supported  at  the  top  by  a  2  x  4  inch  horizontal,  braced  to  the  platform. 
The  scratch  coat  consisted  of  dry  mixed  1 12  Atlas  Portland  Cement  with  an 
addition  of  6  per  cent,  of  hydrated  lime  and  the  finish  coat  was  made  of  i  part 
Atlas  Portland  Cement  and  2  parts  sand. 

The  lath  reinforcing  was  erected  by  the  Truss  Metal  Lath  Co.,  New  York, 
sub-contractors  of  Thos.  G.  Carlin,  who  had  the  general  contract  for  the  work 
under  the  supervision  of  the  Brooklyn  Rapid  Transit  Co.,  Mr.  W.  S.  Menden, 
Chief  Engineer. 


FIG.  161.— MASKED  TRUSS,  56TH  STREET,  NEW  YORK,  N.  Y.  C.  &  H.  R.  R.  R. 


206 


BRIDGE  U  44,  C.,  M.  &  ST.  P.  RY. 


TRIPLE-ARCH  BRIDGE,  ILL.  CENTRAL  R.  R. 
207 


CHUTE  FOR  DEPOSITING  CONCRETE,  PAINSVILLE  BRIDGE. 


FOUR-TRACK   REINFORCED  CONCRETE  ARCH  OVER  GRAND  RIVER,  PAINSVILLE,  OHIO,  LAKE  SHORE 

&  MICHIGAN  SOUTHERN  RY. 

Span  of  center  arch,  160  ft.  0  in.     Total  length  of  bridge,  382  ft.  0  in.     Rise  of  center  arch,  58  ft.  3  in.     Total 
width  of  bridge,  65  ft.  0  in.     Span  of  each  end  arch,  70  ft.  0  in.     Cubic  yards  of  concrete,  25,150. 

208 


OVERHEAD  HIGHWAY  BRIDGE,  L.  I.  R.  R. 


ARCH  BRIDGE,  SCHENECTADY,  N.  Y.,  N.  Y.  C.  &  H.  R.  R.  R. 
20Q 


GUILFORD  ARCH  BRIDGE,  BIG  FOUR  RY. 


WINNIPEG  VIADUCT,  CANADIAN  PACIFIC  R.  R. 
2IO 


CULVERT  UNDER  LOUISVILLE  &  NASHVILLE  R.  R.  FREIGHT  DEPOT,  KNOXVILLE,  TENN. 


DOUBLE  BOX  CULVERT,  C.,  B.  &  Q.  R.  R. 
211 


r".     .  ...... 

PILE  TRESTLE  OVER  SALT  RIVER,  C.,  B.  &  Q.  R.  R. 


NARROW  GAUGE  TRESTLE,  CATSKILL  MOUNTAINS,  OTIS^R.  R.  CO. 

212 


213 


PIERS,  GRAND  RIVER  BRIDGE,  PERE  MARQUETTE  R.R. 


PIERS,  AT  FOURTH  CROSSING,  MISSOULA  RIVER,  N.  P.  RY. 
214 


215 


ABUTMENT  AND  PIER,  BROWNS  MILLS,  VT.,  VERMONT  CENTRAL  R.  R. 


ABUTMENT  FOR  MOTT  AVE.  BRIDGE,  N.  Y.  C.  &  H.  R.  R.  R. 

2x6 


BISMARK,  N.  D.,  DEPOT,  CANADIAN  PACIFIC  RY. 


SANTA  BARBARA,  CAL.,  STATION,  SOUTHERN  PACIFIC  RY. 
217 


YONKERS  IMP.  RETAINING  WALL  BEFORE  FILLING,  N.  Y.  C.  &  H.  R.  R.  R. 


RETAINING  WALL,  D.,  L.    &  W.  R.  R.  TRACK  ELEVATION,  NEWARK,  N.  J. 

218 


COALING  STATION,  POLLOCK,  PA.,  PITTSBURG  &  LAKE  ERIE  R.  R. 
2IQ 


CRUSHED  STONE  HANDLING  TRESTLE,  SPRINGFIELD,  MASS. 


RETAIL  COAL  POCKET,  MURRAY  HILL,  N.  J.,  D.,  L.  &  W.  R.  R. 
22O 


ar^Tfeg^ 


ANTHRACITE  SCREENINGS  POCKET,  NEWARK,  N.  J.,  D.,  L.  &  W.  R.  R. 


221 


SUPPORT  FOR  WATER  TANK,  WATERBURY,  CONN.,  N.  YM  N.  H.  &  H.  R.  R. 


480,000-GALLON  WATER  TOWER,  CANANEA,  YAQUIS  &  PACIFIC  R.  R. 

222 


BAKERSFIELD,  CAL.,  ROUNDHOUSE,  A.,  T.  &  S.  F.  RY. 


AMERICAN  MALTING  CO.  ELEVATOR,  BUFFALO,  N.  Y. 
223 


SAN  BERNARDINO  ROUNDHOUSE,  A.,  T.  &  S.  F.  RY. 


BUFFALO  ROUNDHOUSE,  LEHIGH  VALLEY  R.  R. 
224 


PORTAL  8TH  STREET  TUNNEL,  KANSAS  CITY,  MO. 


INTERIOR  8TH  STREET  TUNNEL,  KANSAS  CITY,  MO. 
225 


GALESBURG  SUBWAY,  C.,  B.  &   Q.  R.  R. 


ENTRANCEIOF  VTUNNEL.VWEEHAWKEN,-  N.  j.,  WEST  SHORE  R.  R. 

226 


227 


PORTABLE  SUB-STATION,  L.  I.  R.  R. 


•IIJII 


u 


riiliititi 


PATTERN  STORAGE  BUILDING,  C.,  M.  &  ST.  P.  RY. 
228 


Reinforced  Concrete 

in  Factory 
Construction 


Published  by 

The  Atlas  Portland  Cement  Company 
30  Broad  Street,  New  York,  N.  Y. 


Copyright  by 
THE  ATLAS  PORTLAND  CEMENT   COMPANY. 

1907. 
All   rights  reserved. 


INTRODUCTION 


Reinforced  concrete  has  provided  for  the  manufacturer  an 
entirely  new  building  material.  IndestrucStible,  economical 
and  fireproof,  it  offers  under  most  conditions  features  of  ad- 
vantage over  every  other  type  of  construction.  The  devel- 
opment has  naturally  been  greatest  in  the  larger  centers  of 
population,  but  it  is  extending  rapidly  to  the  remoter  dis- 
tricts, and,  indeed,  wherever  new  buildings  are  contemplated. 

This  widespread  interest  demands  an  authoritative  treat- 
ment, and  The  Atlas  Portland  Cement  Company  has 
embraced  this  opportunity  to  present  to  the  manufacturer, 
and  also  to  the  architect  and  the  engineer  who  are  not  con- 
crete specialists,  a  brief  treatise  on  reinforced  concrete  for 
factory  construction,  with  a  view  of  giving  a  comprehensive 
idea  of  the  advantages  and  limitations  of  the  material  as 
adapted  to  the  factory,  and  a  demonstration  of  its  value  as 
illustrated  in  a  variety  of  buildings  in  different  localities. 

The  work  has  been  prepared  by  a  consulting  engineer, 
Mr.  Sanford  E.  Thompson,  who  is  well  qualified  to  treat 
the  subject  as  an  expert  authority.  The  Atlas  Portland 
Cement  Company,  occupying,  as  it  does,  a  somewhat  unique 
position  among  cement  manufacturers,  with  its  wide  reputa- 
tion for  a  thoroughly  uniform  and  satisfactory  produdl,  and 


its  immense  production  —  greater  in  1907  than  that  of  any 
other  four  cement  manufacturers  in  the  world  —  commends 
the  book  to  its  readers  with  the  hope  that  it  may  prove  a 
fitting  sequel  to  the  former  publications  of  the  company  — 
"Concrete  Construction  About  the  Home  and  On  the  Farm" 
and  "  Concrete  Country  Residences." 

THE  ATLAS  PORTLAND  CEMENT  COMPANY. 
New  York,  November,  1907. 


PREFACE. 


This  book  may  not  be  regarded  as  a  complete  treatise  on  concrete  factory 
construction,  but  it  has  been  the  aim  to  present  details  of  this  type  of  con- 
struction and  a  careful  description  of  typical  examples  of  concrete  buildings 
selected  from  various  sections  of  the  country  and  erected  by  representative 
builders.  Suggestions  are  thus  offered  to  the  factory  owner  who  contemplates 
building  in  reinforced  concrete,  while  at  the  same  time  the  practical  details 
may  prove  of  value  to  architects,  engineers  and  builders. 

The  first  chapter  presents  to  the  manufacturer  a  brief  review  of  the 
qualities  of  reinforced  concrete  in  comparison  with  other  materials  for  factory 
buildings,  and  this  is  followed  by  a  chapter  giving  in  considerable  detail  the 
general  principles  of  design  with  information  in  regard  to  methods  of  con- 
struction. Chapter  III  treats  of  the  selection  of  the  aggregates.  These 
general  chapters  are  followed  by  ten  chapters,  each  describing  in  full  some 
one  shop,  factory  or  warehouse  of  reinforced  concrete,  selected  with  a  view 
of  presenting  a  variety  of  the  more  usual  types  of  factory  and  warehouse  con- 
struction. 

Chapter  XIV  outlines  with  illustrations  many  of  the  styles  and  systems 
of  reinforcement  in  common  use  in  building  construction,  and  briefly  refers 
to  examples  of  concrete  block  walls,  surface  finish,  concrete  pile  foundations 
and  tanks,  each  illustrated  by  photographs. 

All  illustrations,  excepting  a  part  of  those  in  Chapter  XIV,  have  been 
prepared  especially  for  this  book.  The  half-tones  are  made  from  original 
photographs,  and  the  designs  from  drawings  furnished  by  the  engineers  and 
contractors,  or  reproduced  in  the  office  of  the  author  from  the  original  plans. 
In  this  way  a  number  of  details  are  shown  which  seldom  appear  in  print. 
Care  has  been  taken  throughout  to  give  complete  measurements  so  that  the 
figures  may  be  used  as  a  guide  to  new  construction  work. 

3 


The  Atlas  Portland  Cement  Company,  and  the  undersigned,  desire  to 
letters  received  by  them  from  the  owners  of  the  plants  described  in  the  various 
chapters.  A  number  of  photographs  of  other  reinforced  concrete  factories 
are  also  reproduced. 

The  Atlas  Portland  Cement  Company,  and  the  undersigned,  desire  to 
express  their  appreciation  of  the  courtesies  extended  by  individuals  and  com- 
panies who  have  kindly  furnished  plans  and  data  for  incorporation  into  the 

descriptive  chapters. 

SANFORD  E.  THOMPSON, 
November  i,  1907.  Newton  Highlands,  Mass. 


CONTENTS. 


CHAPTER  I. 

Factory  Construction. 

PAGE 

Cost    12 

Approximate  Cost  per  Cubic  Foot 12 

Safety  of  Reinforced  Concrete  Construction    13 

Durability    13 

Fire  Resistance    14 

Insurance 15 

Stiffness   15 

Freedom  from  Vibration 16 

Versatility  of  Design 16 

Light    16 

Watertightness    16 

Cleanliness    17 

Rapidity  of  Construction 17 

Alterations    t. 17 

Hanging  Shafting   17 

Bedding   Machinery 17 

Auxiliary  Equipment   18 

Foundations    18 

Power  Development 18 

Partitions 18 

Roof    18 

Tanks   18 

Letting  the  Contract 19 

Growth  of  Reinforced  Concrete  Construction    19 

Appendix:  Fire  Insurance  on  Reinforced  Concrete   21 

By  L.  H.  Kunhardt. 

CHAPTER  II. 
Design  and  Construction. 

Cement 24 

Brief  Specifications  for  Portland  Cement    25 

Specifications  for  Materials   25 

5 


PAGE 

Sand    •  •  •  ° 25 

Screenings   25 

Gravel 25 

Broken  Stone   25 

Water    26 

Reinforced  Steel 26 

Proportions  of  Materials   26 

Machine  Mixing 26 

Consistency 26 

Placing 27 

Surfaces   27 

Forms  27 

Foundations    28 

Basement  Floor 30 

Design  of  Floor  System 30 

Columns 35 

Walls    36 

Roofs    36 

Construction   36 


CHAPTER  III. 

Concrete  Aggregates. 

Effect  of  Different  Aggregates  upon  the  Strength  of  Mortar  and  Concrete  38 

General  Principles  for  Selecting  Stone 38 

Comparative  Values  of  Different  Stone 39 

General  Principles  for  Selecting  Sand 40 

Testing   Sand 42 

Calculating  Relative  Strengths  of  Mortars 43 

Testing  Concrete  Aggregates   45 

Proportioning  Concrete  45 


CHAPTER  IV. 
Pacific  Coast  Borax  Refinery. 

Design    47 

Proportions  of  the  Concrete 52 

Construction    54 

The  Fire   55 

6 


CHAPTER  V. 

Ketterlinus  Building. 

PAGE 

Design    61 

Columns 64 

Column  Footings 65 

Floor  System   66 

Stairs    67 

Walls    68 

Roof 68 

Construction   69 

Cost    73 

Insurance 73 


CHAPTER  VI. 

Lynn  Storage  Warehouse. 

Floor  Construction 75 

Floor   Specifications    78 

Floor  Surface 80 

Test  of  Floor 80 

Columns 80 

Construction    82 

Forms 86 

Wall   Construction    87 

Partitions 87 

Waterproofing    87 


CHAPTER  VII. 
Bullock  Electric   Machine   Shop. 

Design    89 

Columns    93 

Crane   Brackets    94 

Floor  System   94 

Walls    95 

Construction  Plant   96 

Gang , 99 

Forms    99 

7 


CHAPTER  VIII. 

Wholesale  Merchants'  Warehouse. 

PAGE 

Layout    103 

Beams  and  Slabs 104 

Columns 107 

Walls 108 

Stairs    109 

Coal  Trestle 109 

Construction    109 

Cost    117 

CHAPTER  IX. 

Bush  Model  Factory. 

Design    119 

Columns    122 

Floor    System    123 

Walls 125 

Construction   125 

CHAPTER  X. 
Packard  Motor  Car  Factory. 

Floor  System  131 

Columns    136 

Stairs    138 

Construction   138 

Forms   138 

CHAPTER  XI. 
Textile  Machine  Works. 

Columns    147 

Floor  System   151 

Cost 156 

CHAPTER  XII. 
Forbes  Cold  Storage  Warehouse. 

Details  of  Construction  160 

Girder  Frames   165 

Forms  ^7 

Construction  Plant 167 

Materials  and  Cost 167 

8 


CHAPTER  XIII. 

Blacksmith  and  Boiler  Shop  of  the  Atlas  Portland  Cement  Co. 

PAGE 

Design    , 169 

Construction 169 

Coal  Trestle    176 

CHAPTER  XIV. 
Details  of  Construction. 

Systems  of  Reinforcement 178 

Factory  Molded  Concrete   190 

Concrete  Block  Walls   194 

Concrete  Metal  Walls   195 

Surface  Finish   195 

Concrete  Pile  Foundations 197 

Tanks    202 

MISCELLANEOUS  BUILDINGS. 
LETTERS. 


CHAPTER  L 


FACTORY  CONSTRUCTION. 

A  manufacturer  about  to  build  a  factory  or  warehouse  must  choose  be- 
tween several  types  of  construction.  In  this  selection  the  governing  considera- 
tions are  cost,  safety,  durability,  and  fire  protection,  while  many  minor  factors 
enter  into  each  individual  case. 

In  this  opening  chapter  the  qualities  of  the  different  materials  available 
for  factories  are  discussed  with  special  reference  to  the  reinforced  concrete. 

Types  of  buildings  for  mills,  factories,  and  warehouses  may  be  classified 
as  follows : 

(1)  Frame  construction; 

(2)  Steel  construction ; 

(3)  Mill  or  slow  burning  construction; 

(4)  Reinforced  concrete  construction. 

The  first  and  cheapest  type  of  frame  construction  may  be  neglected  as 
unsuitable  for  permanent  installation  because  of  its  lack  of  durability  and  its 
fire  risk.  Board  walls,  narrow  floor  joists,  board  floors  and  roofs,  not  only  do 
not  protect  against  fire,  but  in  themselves  afford  fuel  even  when  the  contents 
of  a  factory  are  not  combustible. 

Steel  construction  with  concrete  or  tile  floors,  provided  the  steel  is  itself 
protected  from  fire  by  concrete  or  tile,  is  efficient  and  durable,  but  its  first 
cost  alone  will  usually  prohibit  its  use  for  the  ordinary  factory  building. 

Mill,  or  "slow  burning,"  construction,  as  it  is  sometimes  called  to  dis- 
tinguish it  from  fireproof  construction,  consists  of  brick,  stone,  or  concrete 
walls,  with  wooden  columns,  timber  floor  beams  and  thick  plank  floors,  which 
although  not  fireproof,  are  all  so  heavy  as  to  retard  the  progress  of  a  fire  and 
thus  afford  a  measure  of  protection. 

Reinforced  concrete,  through  the  reduction  in  price  of  first-class  Port- 
land cement  and  the  greater  perfection  of  the  principles  of  design,  has  lately 
become  a  formidable  competitor  to  both  steel  and  slow  burning  construction, 
a  competitor  of  steel,  not  only  for  factories  and  warehouses,  but  also  for  office 
buildings,  hotels  and  apartment  houses,  because  of  its  lower  cost,  shorter 
time  of  construction,  and  freedom  from  vibration ;  a  competitor  of  slow 
burning  construction  because  of  its  greater  fire  protection,  lower  insurance 
rates,  durability,  freedom  from  repairs  and  renewals,  and  even  in  many  cases, 
its  lower  actual  cost. 

ii 


COST. 

As  a  fundamental  principle  in  mill  and  factory  construction,  the  cost 
must  be  such  that  the  outlay  for  interest  on  construction,  running  expenses, 
and  maintenance,  shall  be  at  the  lowest  possible  minimum  consistent  with 
conservative  design  and  the  requirements  of  operation.  A  wooden  building  is 
cheap  in  first  cost,  and  therefore  in  interest  charges,  but  is  expensive  in  in- 
surance and  repairs,  while  the  risk  of  the  loss  in  production  after  a  fire,  for 
which  no  insurance  provides,  may  far  counterbalance  any  theoretical  saving. 

As  a  general  proposition,  reinforced  concrete  is  almost  invariably  the 
lowest  priced  fireproof  material  suitable  for  factory  construction.  The  cost 
is  nearly  always  lower  than  that  for  brick  and  tile,  and  with  lumber  at  a 
high  price,  it  is  frequently  even  lower  than  brick  and  timber,  with  the  added 
advantage  of  durability  and  fire  protection. 

In  comparing  the  cost  of  different  building  materials,  one  must  bear  in 
mind  that  the  concrete  portion  of  the  building  is  only  a  part  of  the  total  cost. 
Since  the  cost  of  the  finish  and  trim  may  equal  or  exceed  that  of  the  bare  struc- 
ture, even  if  the  concrete  itself  cost,  say,  10  per  cent,  more  than  brick  and  tim- 
ber, the  cost  of  the  building  complete  may  not  be  5  per  cent,  greater  than  with 
timber  interior.  The  lower  insurance  rates  will  partly  offset  this  even  if  there 
is  no  other  economical  advantage  for  the  fireproof  structure. 

The  exact  cost  of  a  building  in  any  case  is  governed  by  local  conditions. 
In  reinforced  concrete,  the  design,  the  loading  for  which  it  must  be  adapted 
the  price  of  cement,  the  cost  of  obtaining  suitable  sand  and  broken  stone  or 
gravel,  the  price  of  lumber  for  forms,  the  wages  of  the  laborers  and  carpenters, 
are  all  factors  entering  into  the  estimate.  Reinforced  concrete  is  largely  laid 
by  common  labor,  so  that  high  rates  for  skilled  laborers  affect  it  less  than  many 
other  building  materials. 


APPROXIMATE  COST  PER  CUBIC  FOOT, 

As  a  general  proposition,  it  may  be  stated  that  the  cost  of  reinforced  con- 
crete factories  finished  complete  with  heating,  lighting,  plumbing,  and  eleva- 
tors, but  without  machinery  may  run,  under  actual  conditions,  from  8  cents 
per  cubic  foot  of  total  volume  measured  from  footings  to  roof,  to  12  cents  per 
cubic  foot.  The  former  price  may  apply  where  the  building  is  erected  simply 
for  factory  purposes  with  uniform  floor  loading,  symmetrical  design — permit- 
ting the  forms  to  be  used  over  and  over  again — and  with  materials  at  moderate 
prices.  Several  of  the  buildings  of  simple  design  described  in  the  chapters 
which  follow  come  in  this  class.  The  higher  price  will  usually  cover  such  a 
manufacturing  building  as  the  Ketterlinus,  described  in  Chapter  V,  located  in 
a  restricted  district,  and  where  the  appearance  both  of  the  exterior  and  interior 
must  be  pleasing.  This  does  not  include  in  either  case  interior  plastering  or 
partitions. 

12 


SAFETY  OF  REINFORCED  CONCRETE  CONSTRUCTION. 

In  any  type  of  building  there  is  more  or  less  danger  of  accident  during  erec- 
tion. It  may  be  stated,  however,  that  with  ordinary  skill  in  design  and  con- 
struction there  is  no  more  liability  of  failure  with  reinforced  concrete  than  with 
other  structural  materials.  Accidents  which  have  occurred  can  be  traced  in- 
variably to  a  disregard  of  elementary  principles  of  design  or  construction. 

Every  little  while  failures  of  steel  structures  occur  through  neglect  of  such 
details  as  proper  riveting,  sufficient  bracing,  or  competent  design.  Even  brick 
buildings  are  by  no  means  immune  from  accidents  through  poor  workmanship 
or  ignorance.  For  example,  on  a  single  night  in  the  spring  of  1905,  the  walls 
of  several  apartment  houses  in  process  of  building  in  different  parts  of  New 
York  city  fell  down,  the  cause  being  undoubtedly  the  freezing  and  thawing  of 
the  mortar.  Yet  one  does  not  condemn  either  steel  or  brick  as  a  building  ma- 
terial. Such  failures,  whether  in  steel,  brick  or  concrete,  have  simply  empha- 
sized the  fact,  and  it  cannot  be  too  strongly  insisted  upon,  that  a  thorough 
knowledge  of  the  theory  of  design  is  essential  as  well  as  experience  and  vigil- 
ant inspection  during  erection. 

For  reinforced  concrete  buildings  it  is  especially  important  that  the  de- 
signer be  competent,  and  that  the  builder  be  of  undoubted  experience  and  with 
a  knowledge  of  the  fundamental  principles  of  this  particular  type  of  construc- 
tion. By  this  it  is  not  meant  that  the  builder  be  an  expert  mathematician,  but 
he  should  be  able  to  recognize  the  necessity  for  placing  the  steel  near  the  bot- 
tom surface  of  the  beams  and  slabs,  of  accurately  placing  all  the  steel 
exactly  as  called  for  on  the  plans,  uniform  proportioning  of  the  concrete, 
of  breaking  joints  at  the  proper  places,  of  laying  beams  and  slabs  as  a 
monolithic  floor  system,  and  of  determining  the  hardness  of  the  concrete 
before  removing  forms  and  shores. 

The  safety  of  a  well  designed  reinforced  concrete  building  increases  with 
age,  the  concrete  growing  harder  and  the  bond  with  the  steel  becoming 
stronger. 

DURABILITY. 

There  is  scarcely  any  class  of  manufacture  which  is  not  now  being  carried 
on  in  a  reinforced  concrete  building.  It  is  adaptable  to  any  weight  of  loading 
to  high  speed  and  heavy  machinery,  as  well  as  to  light  machine  tools,  and  to 
almost  any  style  of  design. 

Recent  scientific  experiments,  as  well  as  actual  experience,  are  favorable 
to  the  use  of  concrete  under  repeated  and  vibrating  loads. 

The  use  of  concrete  in  brackets  for  supporting  crane  runs,  as  in  the  Bul- 
lock shop,  Chapter  VII,  is  an  interesting  example  of  severe  application  of  load- 
ing. Several  concrete  buildings  in  San  Francisco  withstood  the  shock  of  the 
earthquake,  while  those  around  them  of  brick  and  stone  and  wood  were  des- 
troyed. 

13 


While  most  materials  tend  to  rust  or  decay  with  time,  concrete  under  proper 
conditions  continues  to  increase  in  strength  for  months  or  even  for  years. 

Concrete  expands  and  contracts  with  changes  of  temperature.  Its  co- 
efficient of  expansion,  that  is,  its  expansion  in  a  unit  length  for  each  degree  of 
increase  in  temperature,  is  almost  identical  with  steel,  and  on  this  account 
there  is  no  tendency  of  the  steel  to  separate  from  the  concrete,  and  they  act 
together  under  all  conditions.  As  in  building  with  other  materials,  provision 
must  be  made  in  long  walls  or  other  surfaces  for  the  expansion  and  contraction 
due  to  temperature,  by  placing  occasional  expansion  joints  or  by  adding  extra 
steel.  In  factories  of  ordinary  size,  no  special  provision  need  be  made,  as  the 
regular  steel  reinforcement  will  prevent  cracking. 

Special  precautions  are  necessary  for  laying  concrete  in  sea  water.  A  first 
class  cement  must  be  selected,  rich  proportions  used — at  least  i  :2 14 — a  coarse 
sand,  and  well  proportioned  aggregate  which  v/ill  produce  a  dense  impervious 
mass. 

FIRE  RESISTANCE. 

Reinforced  concrete  ranks  with  the  best  fireproof  materials,  and  it  is  this 
quality  perhaps  more  than  any  other  which  is  responsible  for  the  enormous 
increase  in  its  use  for  factories. 

Intense  heat  injures  the  surface  of  the  concrete,  but  it  is  so  good  a  non- 
conductor that  if  sufficiently  thick,  it  provides  ample  protection  for  the  steel 
reinforcement,  and  the  interior  of  the  mass  is  unaffected  even  in  unusually 
severe  fires. 

For  efficient  fire  protection  in  slabs,  under  ordinary  conditions  the  lower 
surface  of  the  steel  rods  should  be  at  least  3/4  inch  above  the  bottom  of  the  slab. 
In  beams,  girders  and  columns,  a  thickness  of  i%  to  2^  inches  of  concrete 
outside  of  the  steel,  varying  with  the  size  and  importance  of  the  member,  and 
the  liability  to  severe  treatment,  is  in  general  sufficient.  In  columns,  whose 
size  is  governed  by  the  loads  to  be  sustained,  an  excess  of  sectional  area  should 
be  provided  so  that  if,  say,  one  inch  of  the  surface  is  injured  by  fire,  there  will 
still  be  enough  concrete  to  sustain  any  loads  which  may  subsequently  come 
upon  it. 

One  of  the  advantages  of  concrete  construction  as  a  fireproof  material  is 
that  the  design  may  be  adapted  to  the  local  conditions.  For  example,  in  an 
isolated  machine  shop  where  scarcely  any  inflammable  materials  are  stored, 
it  is  a  waste  of  money  to  provide  a  thick  mass  of  concrete  simply  to  resist  fire. 
On  the  other  hand,  for  a  factory  or  warehouse  storing  a  product  capable  of 
producing  not  merely  a  hot  fire — a  hot  short  fire  will  not  damage  seriously — 
but  an  intense  heat  of  long  duration,  special  provision  may  be  made  by  using 
an  excess  area  of  concrete  perhaps  two  or  three  inches  thick. 

Actual  fires  are  the  best  test  of  a  material.  One  of  the  most  severe  on 
record  occurred  in  the  Pacific  Coast  Borax  Refinery  described  in  Chapter  IV, 
and  the  concrete  there,  as  well  as  in  the  Baltimore  and  San  Francisco  fires, 
made  an  excellent  record. 


The  best  fire  resistance  materials  for  concrete  are  first-class  Portland 
cement  with  quartz  sand  and  broken  trap  rock.  Limestone  aggregate  will  not 
stand  the  heat  so  well  as  trap,  while  the  particles  of  gravel  are  more  easily 
loosened  by  extreme  heat.  Neither  of  these  materials,  however,  if  of  good 
quality,  need  be  rejected  for  building  construction  unless  the  demands  are 
especially  exacting  and  the  liability  to  fire  great.  Cinders  make  a  good  aggre- 
gate for  fire  resistance,  but  the  concrete  made  with  them  is  not  strong  enough 
for  reinforced  concrete  construction  except  in  slabs  of  short  span  or  in  partition 
walls. 

The  fire  resistance  of  concrete  increases  with  age,  as  the  water  held  in  the 
pores  is  taken  up  chemically  and  is  evaporated. 

INSURANCE. 

When  reinforced  concrete  first  came  to  the  front  for  factories  and  ware- 
houses, the  insurance  companies  hesitated  to  assume  such  buildings  as  first- 
class  risks.  However,  examination  and  tests  have  gradually  convinced  the 
most  skeptical  of  their  true  fire  resistance,  until  now  structures  of  this  mate- 
rial are  sought  after  and  given  the  lowest  rates  of  insurance. 

Mr.  L.  H.  Kunhardt,  Vice-President  and  Engineer  of  one  of  the  oldest  of 
the  Factory  Mutual  Insurance  Companies,  which  have  for  years  played  a  lead- 
ing part  in  the  development  of  mill  construction,  and  the  science  of  fire  pro- 
tection engineering  and  the  consequent  reduction  of  fire  losses,  presents  in  an 
Appendix  to  this  chapter  (p.  21)  very  instructive  figures  comparing  the  costs 
of  insurance  upon  several  types  of  factories  for  various  classes  of  manufacture. 
Mr.  Kunhardt  also  indicates  the  means  by  which  concrete  may  be  utilized  in 
reducing  even  the  present  low  rates  of  insurance  upon  buildings  protected  by 
efficient  fire  apparatus. 

From  the  statements  there  given  by  so  eminent  an  authority  on  mill  in- 
surance, we  may  conclude  that  a  well-designed  reinforced  factory  with  con- 
tinuous floors  (i)  offers  security  against  disastrous  fires  and  total  loss  of 
structure ;  (2)  reduces  danger  to  contents  by  preventing  the  spread  of  a  fire ; 
(3)  prevents  damage  by  water  from  story  to  story;  (4)  makes  sprinklers  un- 
necessary in  buildings  whose  contents  is  not  inflammable ;  (5)  reduces  danger 
of  panic  and  loss  of  life  among  employees  in  case  of  fire. 

STIFFNESS. 

A  reinforced  concrete  building  really  resembles  a  structure  carved  out  of 
a  single  block  of  solid  rock.  It  is  monolithic  throughout.  The  beams  and 
girders  are  continuous  from  side  to  side  and  from  end  to  end  of  the  building, 
while  even  the  floor  slab  itself  forms  a  part  of  the  beams,  and  the  columns  are 
also  either  coincident  with  them  or  else  tied  to  them  by  their  vertical  steel 
rods. 

All  this  accounts  for  the  extraordinary  stiffness  and  solidity  of  a  rein- 
forced concrete  structure,  and  differentiates  it  from  timber  construction  where 

15 


positive  joints  occur  over  every  column;  and  even  from  steel  construction,  in 
which  the  deflection  is  greater. 

FREEDOM  FROM  VIBRATION. 

This  solidity  and  entire  lack  of  joints,  and  particularly  the  weight  of  the 
material,  especially  adapts  it  to  both  high  speed  and  heavy  machinery.  The 
vibrations  are  deadened  and  absorbed  in  a  way  which  is  impossible  in  steel 
structures. 

An  interesting  example  of  this  fact  is  furnished  in  the  Ketterlinus  building 
described  in  Chapter  V,  where  the  vibration  and  jar  in  the  new  concrete 
building  are  remarkably  less  than  in  the  adjacent  steel  and  tile  structure  carry- 
ing the  same  type  of  machinery. 

VERSATILITY  OF  DESIGN. 

Steel  rods  are  set  in  the  concrete,  to  provide  tensile  strength,  in  such 
quantity  and  location  as  is  needed  for  special  loading  for  which  it  is  designed. 
Consequently,  spans  can  be  constructed  of  any  reasonable  length,  either  long 
or  short,  and  column  spacing  may  be  adapted  to  the  requirements  of  operation. 
Because  of  the  weight  of  the  concrete,  which  must  itself  be  borne  by  the 
strength  of  the  member,  very  long  beam  and  girder  spans  are  relatively  more 
expensive  than  the  more  ordinary  spans  of  15  or  20  feet.  Similarly,  the  cost 
of  floor  slabs  per  square  foot  increases  appreciably  with  their  span.  These 
limitations  are  economical  rather  than  theoretical,  and  every  design  should 
therefore  be  studied  thoroughly  to  produce  the  best  results  at  least  cost,  and 
to  adapt  the  structure  to  the  class  of  manufacture  or  storage  for  which  it  is 
intended. 

The  rule  applies  to  reinforced  concrete  as  well  as  to  other  structures,  that 
the  industrial  portion  of  the  plant,  the  arrangement  of  the  machines,  and  of  the 
transmission  machinery,  should  be  first  designed  and  the  structure  adapted 
to  give  a  minimum  operating  expense. 

LIGHT. 

A  special  feature  of  reinforced  concrete  construction  is  the  possibility  of 
building  practically  the  entire  wall  of  glass,  so  as  to  afford  a  maximum  amount 
of  light.  Concrete  is  so  strong  that  the  columns  can  be  made  of  small  size 
and  the  windows  carried  by  shallow  beams.  The  window  area  may  thus  cover 
a  very  large  percentage  of  the  wall  surface. 

WATERTIGHTNESS. 

In  some  classes  of  manufacture  where  water  is  freely  used,  as  in  paper 
and  pulp  mills,  it  is  essential  that  the  floors  shall  be  tight  so  that  water  cannot 
fall  into  the  product  on  the  floor  below  or  on  to  the  belting.  In  case  of  fire 
a  watertight  floor  prevents  damage  from  water  to  the  machinery  and  materials 

16 


in  the  stories  below.    A  concrete  floor  with  granolithic  surface  is  practically 
impervious  to  water. 

CLEANLINESS. 

Concrete  floors  may  be  laid  on  a  slight  slope  with  a  drain  along  the  sides 
of  the  room  so  as  to  carry  off  all  water  and  permit  flushing  with  the  hose. 
Concrete  is  vermin  proof. 

RAPIDITY  OF  CONSTRUCTION. 

The  speed  with  which  a  reinforced  concrete  building  can  be  completed  is 
due  in  a  great  measure  to  the  fact  that  there  need  be  no  waiting  for  materials. 
Sand  and  stone  are  always  available ;  Portland  cement  is  now  supplied  by  large 
mills  with  immense  storage  capacity ;  and  steel  rods  are  kept  in  stock,  so  that 
a  building  can  be  commenced  as  soon  as  the  plans  are  completed  and  no  de- 
lays need  be  incurred  in  ordering  special  shapes  and  awaiting  their  shipment 
from  the  mills. 

In  general,  under  good  superintendence  the  rate  of  progress  of  a  reinforced 
concrete  factory  may  be  as  fast  as  one-half  story  or  even  one  story  per  week. 

ALTERATIONS. 

Reinforced  concrete  is  not  suitable  for  a  temporary  structure.  It  is  too 
difficult  a  matter  to  tear  it  down.  Radical  changes  in  construction  are  not 
readily  made,  but  holes  may  be  cut  in  walls  and  floors  at  greater  expense  than 
in  wood,  but  without  serious  difficulty. 

HANGING  SHAFTING. 

Provision  may  be  made  for  shafting  by  placing  bolts  or  sockets,  in  the 
beams  to  connect  with  pillow  blocks  for  special  lines  of  shafting,  or  such  con- 
nections may  be  made  at  regular  intervals  so  that  timbers  or  steel  frames  may 
be  bolted  and  shafting,  or  tracks  for  conveying  material,  supported  at  any 
positions  subsequently  specified. 

BEDDING  MACHINERY. 

All  ordinary  machinery  can  be  directly  bolted  to  the  concrete  floors  by 
drilling  holes  into  them  and  setting  lag-screws  or  through-bolts.  If  a  concrete 
foundation  is  built  for  a  special  machine  or  engine,  it  may  be  bedded  directly 
upon  the  concrete.  To  level  the  machine  on  a  permanent  base,  it  may  be 
leveled  an  inch  or  two  above  the  foundation  proper  and  grouted.  A  dam  of 
sand  is  built  around  the  machine,  and  grout,  made  of  Portland  cement  mortar 
in  proportions  one  part  cement  to  one  or  two  parts  of  sand  mixed  to  the  con- 
sistency of  thick  cream,  is  poured  into  it  so  as  to  run  under  the  casting,  and 
then  as  this  mortar  hardens  it  is  continually  rammed  with  a  rod  to  prevent 
shrinkage  and  form  a  solid,  permanent  base. 

17 


AUXILIARY  EQUIPMENT. 

Not  only  the  factory  itself,  but  many  of  its  accessories  are  built  of  con- 
crete : 

FOUNDATIONS. 

Foundations  for  engines,  boilers  and  heavy  machines  are  of  course  made 
of  concrete,  this  being  customary  long  before  its  introduction  for  building 
construction.  The  method  of  setting  and  bedding  machinery  has  been  referred 
to  in  a  preceding  paragraph. 

POWER  DEVELOPMENT. 

Dams  either  of  plain  gravity  section  or  of  reinforced  designs,  flumes,  pen 
stocks  and  wheelpits,  are  all  built  of  this  material.  Every  individual  develop- 
ment requires  a  special  design. 

PARTITIONS. 

In  the  factory  itself,  partitions  may  be  made  of  reinforced  concrete  walls 
four  inches  thick,  or  of  concrete  blocks,  as  in  the  Wholesale  Merchants'  Ware- 
house at  Nashville,  Tenn.,  described  in  Chapter  VIII.  For  solid  partition 
walls  and  elevator  wells,  it  is  convenient  to  pour  the  concrete  after  the  floors 
are  laid,  and  this  may  be  done  according  to  the  plan  adopted  by  the  Turner 
Construction  Company  in  the  Bush  Model  Factory  No.  2  (see  Chapter  IX), 
by  leaving  a  slot  in  the  floor  at  the  proposed  location  for  the  partition. 

ROOF. 

Naturally,  the  roof  of  a  reinforced  concrete  building  is  of  the  same  ma- 
terial, designed  to  carry  the  weight  of  roof  covering  and  snow  which  may  come 
upon  it.  It  is  advisable  to  cover  with  some  form  of  roofing,  as  the  sun  beating 
down  upon  the  concrete  surface  will  tend  to  crack  it. 

If  the  building  is  erected  with  a  view  to  adding  one  or  more  stories,  it  ts 
well  to  build  the  roof  of  wood  or  light  steel  construction  so  that  it  may  be 
readily  taken  down  or  raised. 

TANKS. 

The  making  of  durable  tanks  is  one  of  the  problems  in  many  factories. 
This  is  being  solved  in  numerous  cases  by  the  use  of  reinforced  concrete,  de- 
signed with  sufficient  steel  to  resist  the  water  pressure.  In  paper  and  pulp 
mills  the  adoption  of  concrete  tanks  is  especially  advisable  because  of  the  fre- 
quent repairs  and  renewals  required  in  wood  construction.  Sulphuric  acid 
and  bleach  liquor  in  pulp  mills  will  attack  any  known  substance,  even  eating 
into  phosphor  bronze.  Concrete  is  by  no  means  exempt  from  this  action,  but 
is  undoubtedly  the  best  material  except  copper  or  bronze,  which  is  of  course 
too  expensive  to  consider. 

18 


Special  attention  should  be  given  to  the  watertightness  of  the  concrete 
so  that  acids  cannot  work  through  it,  and  in  a  small  tank  not  over  10  or  12 
feet  high  the  watertightness  can  be  increased  by  a  coating  of  rich  mortar  on 
the  interior,  troweled  to  a  hard  glassy  surface. 

Limestone  aggregate  should  not  be  used  in  a  tank  to  be  filled  with  acid, 
and  the  steel  reinforcement  should  be  imbedded  at  least  three  inches  or  more. 
Sometimes  it  may  be  well  to  provide  an  excessive  thickness  of  concrete  to 
allow  for  subsequent  wear. 

LETTING  THE  CONTRACT. 

The  contract  for  the  construction  of  a  reinforced  concrete  factory  should 
be  let  only  to  responsible  builders  with  practical  experience  in  this  class  of 
work.  A  man  who  has  simply  laid  concrete  foundations  is  not  competent  to 
erect  a  factory  building.  This  matter  of  experience  cannot  be  too  strongly 
emphasized,  since  every  one  of  the  failures  in  reinforced  concrete  can  be  traced 
directly  to  poor  design  or  to  an  ignorance  and  disregard  on  the  part  of  the 
builder  of  the  fundamental  principles  of  reinforced  concrete  construction. 

If  day  labor  is  employed,  as  in  the  case  of  the  Textile  Machine  Shop,  Chap- 
ter XI,  it  must  be  under  the  direct  superintendence  of  an  engineer  skilled  in 
concrete  construction. 

The  plan  is  frequently  followed  of  requesting  estimates  from  different 
contractors  without  specifying  the  requirements  of  the  design.  As  a  con- 
sequence, the  man  who  dares  to  figure  with  the  smallest  factor  of  safety,  and 
who  thus  would  build  the  poorest  and  weakest  structure,  presents  the  lowest 
bid.  Such  a  possibility  may  be  precluded  by  having  at  least  the  general  plans 
and  specifications  prepared  in  advance  by  a  competent  engineer  or  architect, 
so  that  the  estimates  may  be  compared  with  fairness. 

Concrete  building  construction  is  frequently  performed  on  the  cost-plus- 
a-fixed-sum  or  cost-plus-a-percentage-basis.  These  methods  are  apt  to  result 
in  a  somewhat  higher  cost  for  the  structure  than  competitive  bidding,  al- 
though they  offer  less  temptation  to  the  builder. 

Whatever  plan  is  followed,  one  or  more  competent  inspectors  should  be 
employed  by  the  owners  independent  of  the  contractor  to  see  that  the  work  is 
properly  performed  in  all  its  details. 

GROWTH  OF  REINFORCED  CONCRETE  CONSTRUCTION. 

One  of  the  first  uses  of  reinforced  concrete  in  building  construction  was 
in  the  house  erected  by  W.  E.  Ward  in  1872  at  Port  Chester,  N.  Y.  Some 
twenty  years  earlier  than  this,  in  France,  the  first  combinations  of  iron  im- 
bedded in  concrete  were  made  in  a  small  way.  However,  not  until  the  very 
end  of  the  last  century,  since  1895,  has  concrete  been  employed  commercially 
in  the  construction  of  buildings.  Previously  to  this  it  had  attained  a  wide  use 
in  foundations,  and  at  this  time  its  development  was  beginning  for  such  struc- 
tures as  dams,  sewers  and  subways. 

19 


Two  principal  reasons  may  be  offered  for  this  comparatively  slow  growth 
followed  by  such  marvelous  activity.  In  the  first  place,  Portland  cement 
manufacturers,  beginning  in  Europe  about  the  middle  of  the  igth  century  and 
in  the  United  States  about  1880,  finally  produced  a  grade  of  cement  which, 
with  the  inspection  necessary  for  all  structural  materials,  could  be  depended 
upon  to  give  uniform  and  thoroughly  reliable  results ;  furthermore,  along  with 
the  perfection  of  the  process  of  manufacture,  the  price  gradually  fell  from  the 
high  cost  per  barrel  in  1880  for  imported  cement,  to  a  figure  for  domestic 
Portland  cement  of  equally  good,  if  not  better,  quality,  at  which  concrete  in 
plain  form  could  compete  with  rough  stone  masonry,  and  with  steel  imbedded 
could  compete  with  other  building  materials. 

In  the  second  place,  theoretical  studies  and  practical  experiments  have 
now  produced  rational  and  positive  methods  for  computing  the  strength  of 
concrete  reinforced  with  steel  so  that  absolute  dependence  can  be  placed 
upon  it. 

A  conservative  estimate  places  the  number  of  reinforced  concrete  build- 
ings built  in  the  United  States  during  the  year  1906  as  not  less  than  two  hun- 
dred, while  at  least  as  many  more  have  gone  up  in  concrete  blocks  and  com- 
binations of  concrete  with  other  materials. 

Briefly,  reinforced  concrete  such  as  is  used  for  factory  construction  con- 
sists of  Portland  cement,  sand,  and  gravel  or  broken  stone,  mixed  with  water 
to  a  consistency  that  will  just  flow  sluggishly,  and  in  which  steel  rods  are  im- 
bedded so  as  to  produce  an  artificial  stone  with  many  characteristics  of  steel. 

In  the  earlier  stages  of  reinforced  concrete  and  even  up  to  the  present 
time,  many  patents  of  a  more  or  less  fundamental  character  have  been  granted. 
These  have  taken  the  line  of  special  forms  of  reinforcing  metal  as  well  as 
methods  of  design.  The  principal  styles  of  reinforcement  are  illustrated  in 
Chapter  XIV.  While  it  is  not  necessary  to  encroach  on  any  of  these  inven- 
tions in  building,  the  field  is  worth  careful  consideration,  from  the  viewpoint 
of  economy  and  durability,  as  to  whether  or  not  it  may  be  advisable  to  make 
use  of  them. 


20 


APPENDIX. 


FIRE  INSURANCE  ON  FACTORIES  OF  REINFORCED  CONCRETE. 
By  L.  H.  Kunhardt,  Vice-President. 

Boston  Manufacturers  Mutual  Fire  Insurance  Co. 

In  consideration  of  the  question  of  insurance  on  reinforced  concrete  fac- 
tories, the  problem  simply  resolves  itself  into  a  determination  of  what  the  fire 
and  water  damage  will  be  in  the  event  of  fire  compared  with  that  in  other 
types  of  factory  buildings. 

For  this  purpose  concrete  factories  may  be  divided  into  two  classes: 

i st.  Those  having  contents  which  are  not  inflammable  or  readily  com- 
bustible. In  this  class,  if  wooden  window  frames  and  partitions,  etc.,  have 
been  eliminated,  the  building  as  a  whole  becomes  practically  proof  against 
fire,  provided  there  are  no  outside  exposures,  protection  against  which  would 
require  special  precautions. 

2nd.  Those  having  contents  which  are  more  or  less  combustible,  and 
which  have  in  their  construction  small  amounts  of  inflammable  material,  such 
as  wooden  window  frames  and  top  floors.  In  this  class  the  burning  of  con- 
tents is  the  cause  of  damage  to  the  building,  the  extent  of  which  is  deter- 
mined by  the  character  of  the  contents. 

Of  the  two,  the  latter  class  is  the  one  ordinarily  met,  and  with  which  the 
question  of  insurance  cost  is  therefore  usually  concerned.  The  character  of 
the  occupancy,  details  of  construction  and  conditions  of  various  kinds  inside 
and  outside  the  factory,  and  in  the  various  communities,  have  such  direct 
bearing  on  rates  that  any  statement  as  below  of  comparative  cost  must  be 
extremely  approximate,  but  perhaps  of  value  as  showing  somewhat  the  relative 
costs.  These  in  the  following  table  are  made  upon  the  basis  of  a  building  with- 
out a  standard  fire  equipment,  which  condition  is,  however,  now  rare  in  the 
case  of  first-class  factories  and  warehouses,  even  if  of  fireproof  construction. 

CONCRETE  FACTORIES  VS.  THOSE  OF  WOOD  OR  BRICK. 

Approximate  Yearly  Cost  of  Insurance  Per  $100. 

Exposures,  none;  area  not  large;  good  city  department;  no  private  fire 
apparatus  except  such  as  pails  and  standpipes. 

Add   for  Brick   or 
Wood  Buildings  in 

Brick  Mill  Con-  Wood   Mill   Con-  Small  Towns   and 

struftion  or   Open  struclion  or   Open  Cities    Without 

All  Concrete.                  Joists,  Joists.  Best  of  Water  and 

Bldg.     Contents.             Bldg.        Contents.  Bldg.       Contents.  Fire   Departments. 

General  Storehouse 2oc.        450.                     6oc.        looc.  zooc.       1250.  250. 

Wool  Storehouse aoc.        350.                     400.         6oc.  750.       looc.  250. 

)ffice  Building I5c.         300.                     350.         500.  looc.       1250.  250. 

Cotton  Factory 400.       looc.                   looc.       2ooc.  2000.      3000.  500. 

Tannery 2oc.        4oc.                     750.        looc.  rooc.      looc.  250. 

Shoe  Factory. 250.        8oc.                     750.        looc.  1500.      2ooc.  500. 

Woolen  Mill 3oC.         8oc.                     750.        looc.  1500.      2ooc.  500. 

MachmeShop !5C>         250.                     500.         500.  looc.       looc.  250. 

General  Mercantile  Building 350.         750.                     500.        looc.  looc.       1500.  250. 

NOTE. — These  costs'  are  based  on  the  absence  of  automatic  sprinklers  and  other  private  fire  protective 
appliances  of  the  usual  completely  equipped  building.  They  are  not  schedule  rates,  but  may  be  an  approxima- 
tion to  actual  costs  under  favorable  conditions  based  on  examples  in  various  parts  of  the  country. 

21 


The  table  in  a  general  way  illustrates  the  gain  by  the  use  of  the  better 
type  of  construction,  but  in  factory  work  it  has  long  been  recognized  that  there 
is  a  distinct  hazard  in  the  manufacturing  operations  and  inflammable  con- 
tents which  is  greater  in  degree  than  in  other  classes  of  property.  The  science 
of  fire  protection  with  automatic  sprinklers  and  auxiliary  apparatus  has  there- 
fore attained  such  a  degree  of  perfection  that  the  brick  or  stone  factory  with 
heavy  plank  and  timber  floors  is  obtaining  insurance  at  rates  which  are  lower 
than  those  which  are  possible  on  any  of  the  fireproof  buildings  without  sprink- 
lers. The  real  reason  for  this  lies  in  the  fact  that  the  contents,  including  ma- 
chinery, stock  in  process,  and  finished  goods,  constitute  by  far  the  larger  part 
of  the  value  of  the  plant,  and  these  the  building  alone  cannot  be  expected  to 
protect  when  a  fire  occurs  within,  except  in  so  far  as  the  absence  of  com- 
bustible material  in  construction  may  assist  in  so  doing.  Fire  protection  is 
therefore  needed  for  safety  of  contents,  even  if  the  building  itself  is  practically 
fireproof. 

As  illustrating  the  value  of  fire  protection,  I  would  state  that  in  the  Boston 
Manufacturers'  Mutual  Fire  Insurance  Company,  and  others  of  the  older  of 
the  Factory  Mutual  Companies,  the  average  cost  of  insurance  on  the  better 
class  of  protected  factories  has  now  for  some  years  averaged,  excluding  inter- 
est, less  than  seven  (7)  cents  on  each  one  hundred  dollars  of  risk  taken,  and 
on  first-class  warehouses  connected  with  them,  one-half  this  amount.  These 
figures  can  be  compared  with  the  table  as  illustrating  the  gain  by  the  installa- 
tion of  proper  safeguards  for  preventing  and  extinguishing  fire. 

In  these  same  protected  factories  and  warehouses  the  actual  fire  and  water 
loss  is  less  than  four  (4)  cents  on  each  one  hundred  dollars  of  insurance,  and, 
being  so  small,  it  would  seem  that  they  must  be  almost  impossible  of  reduc- 
tion, but  nevertheless  it  is  possible. 

How  can  this  be  accomplished?  This  is  the  problem  of  the  designer  and 
builder  of  the  concrete  factory. 

i st.  By  avoiding  vertical  openings  through  floors — a  common  fault  in 
many  factories  with  wooden  floors.  To  be  a  perfect  fire  cut-off,  a  floor  should 
be  solid  from  wall  to  wall,  with  stairways,  elevators  and  belts  enclosed  in 
vertical  fireproof  walls  having  fire  doors. 

2nd.  By  provision  for  making  floors  practically  waterproof,  that  water 
may  not  cause  damage  on  floors  below  that  on  which  fire  occurs.  Scuppers 
of  ample  size  to  carry  water  from  floors  to  outside  are  an  essential  part  of  the 
design.  In  the  ordinary  factory  with  wooden  floors,  loss  from  water  is  almost 
invariably  excessive  as  compared  with  the  loss  by  actual  fire. 

3rd.  By  making  the  buildings  as  incombustible  as  possible,  thus  re- 
ducing the  amount  of  material  upon  which  a  fire  may  feed.  Also  by  provision 
for  sufficient  thickness  of  fireproofing  to  thoroughly  insulate  all  steel  work, 
the  fireproofing  being  sufficiently  substantial  that  it  may  not  scale  off  ceilings 
or  columns  at  a  fire  or  from  other  causes,  thus  allowing  failure  of  steel  work, 
by  heating  or  deterioration.  An  owner  is  thus  more  secure  if  the  fire  protec- 
tion or  any  parts  of  it  fail  at  a  critical  moment. 

22 


4th.  By  good  judgment  as  to  the  extent  or  amount  of  fire  protection  re- 
quired in  each  individual  case.  While  the  value  of  the  automatic  sprinkler 
is  recognized  and  the  general  rules  specify  its  installation,  the  Factory  Mutual 
Companies  do  not  require  it  in  the  concrete  building,  except  where  there  is 
sufficient  inflammable  material  in  the  contents  to  furnish  fuel  for  a  fire.  An 
essential  feature  of  good  factory  construction  includes  not  only  consideration 
of  the  building,  but  protection  adequate  to  its  needs  only. 

The  extent  to  which  the  above  is  faithfully  carried  out  will  eventually  be 
the  determining  feature  in  the  cost  of  insurance. 

September  9,  1907. 


CHAPTER  II. 


DESIGN  AND  CONSTRUCTION. 

Concrete  is  an  artificial  stone,  and  if  it  contains  no  steel,  that  is,  if  it  is 
not  reinforced,  it  is  brittle  like  stone.  Just  as  stone  can  be  used  to  support 
enormous  loads,  as  in  foundations,  bridges  and  dams,  provided  it  is  so  placed 
as  to  receive  no  tension  or  pull,  so  can  concrete  stand  heavy  loading  in  com- 
pression with  no  reinforcement. 

Concrete,  however,  has  the  advantage  of  stone,  because  when  built  in 
place,  steel,  which  is  especially  adapted  for  withstanding  pull,  may  be  intro- 
duced at  just  the  right  position  in  the  beam  or  other  member  to  take  this  pull. 
In  an  ordinary  beam  the  upper  surface  is  in  compression  and  the  lower  sur- 
face in  tension;  the  natural  arrangement  of  materials  is  therefore  to  design 
the  beam  so  that  the  upper  part  is  composed  of  concrete,  which  takes  the 
compression,  while  steel  is  embedded  near  the  bottom  to  resist  the  pull  or 
tension.  The  concrete  by  surrounding  the  steel  protects  it  from  rust  and 
fire,  and  because  concrete  and  steel  expand  and  contract  almost  exactly  alike 
when  heated  and  cooled,  they  may  be  used  thus  in  combination  with  no 
danger  of  separation  from  changes  in  temperature. 

It  is  evident  that  to  make  a  safe  combination  of  concrete  and  steel,  it  is 
necessary  to  know  just  how  much  load  each  can  stand,  and  just  where  the 
steel  must  be  located  to  take  every  bit  of  the  tension  which  may  occur  in  any 
part  of  the  beam.  While  in  a  beam  supported  at  the  ends,  the  pull  is  in  the 
bottom  and  the  principal  steel  must  be  as  near  to  the  bottom  as  is  consistent 
with  rust  and  fire  protection,  on  the  other  hand,  when  the  beam  is  built  into 
a  column  or  into  another  beam,  a  load  upon  it  produces  also  a  pull  at  the  top 
of  the  beam  over  its  supports  which  tends  to  crack  it  there.  Furthermore, 
there  are  other  secondary  stresses  in  the  interior  of  the  beam,  partly  shear 
or  tendency  to  slide  and  partly  tension  or  pull,  which  must  be  guarded  against 
by  locating  steel  rods  in  the  proper  places.  Hence  the  necessity,  because  of 
the  complication  in  the  action  of  the  stresses  even  in  a  simple  beam,  that  the 
designers  have  a  knowledge  of  the  principles  of  mechanics  and  the  theories 
involved. 

It  is  not  the  purpose  of  this  book  to  dwell  upon  the  theory  of  design,  but 
instead  to  give  practical  principles  of  construction  to  supplement  the  theory 
which  can  be  obtained  readily  from  other  sources. 

CEMENT. 

Portland  cement  should  always  be  used  for  concrete  building  construc- 

24 


tion  because  it  is  not  only  stronger  than  natural  cement  but  is  more  reliable 
and  hardens  more  quickly. 

The  standard  specifications  adopted  by  the  American  Society  for  Testing 
Materials!  are  generally  adopted  for  important  work  throughout  the  country. 
Brief  specifications  may  be  sufficiently  comprehensive  for  work  of  minor  im- 
portance. 

BRIEF  SPECIFICATIONS  FOR  PORTLAND  CEMENT. 

*A  cement  shall  be  a  first-class  Portland  cement  of  a  standard  brand 
bearing  a  good  reputation,  sound — i.  e.,  not  liable  to  expansion  or  disintegra- 
tion,— fine  and  of  uniform  quality.  It  shall  be  free  from  lumps  and  shall  be 
packed  in  sound  barrels,  or,  if  stored  in  a  dry  place  to  be  used  immediately, 
it  may  be  packed  in  stout  cloth  or  canvas  bags. 

SPECIFICATIONS  FOR  MATERIALS. 

The  following  specifications  are  of  so  general  a  character  as  to  be  applica- 
ble to  nearly  all  kinds  of  concrete  construction.  Local  requirements  limiting 
the  sizes  of  the  particles  and  giving  further  information  may  be  added. 

Sand.* — The  sand  shall  be  clean  and  coarse,  or  a  mixture  of  coarse  and 
fine  grains  with  the  coarse  grains  predominating.  It  shall  be  free  from  clay, 
loam,  mica,  sticks,  organic  matter,  and  other  impurities. 

Screenings. — ^Screenings  or  crusher  dust  from  broken  stone — in  which 
term  is  included  all  particles  passing  a  quarter-inch  screen — by  slightly  alter- 
ing the  proportions  of  the  ingredients,  may  be  substituted  for  the  whole  or  a 
portion  of  the  sand  in  such  proportions  as  to  give  a  dense  mixture  and  the 
same  relative  volumes  of  total  aggregates. 

Gravel.  J — *The  gravel  shall  be  composed  of  clean  pebbles  free  from 
sticks  or  other  foreign  matter  and  containing  no  clay  or  other  materials  ad- 
hering to  the  pebbles  in  such  quantity  that  it  cannot  be  lightly  brushed  off 
with  the  hand  or  removed  by  dipping  in  water.  It  shall  be  screened  to  remove 
the  sand,  which  shall  afterwards  be  remixed  with  it  in  the  required  propor- 
tions. 

Broken  Stone.  J — *The  broken  or  crushed  stone  shall  consist  of  pieces 
of  hard  and  durable  rock,  such  as  trap,  limestone,  granite,  or  conglomerate. 
The  dust  shall  be  removed  by  a  quarter-inch  screen,  to  be  afterwards  mixed 
with  and  used  as  a  part  of  the  sand,  if  desired,  except  that  if  the  product  of 
the  crusher  is  delivered  to  the  mixer  so  regularly  that  the  amount  of  dust 

*  Paragraphs  designated  by  an  asterisk  are  quoted  from  Taylor  &  Thompson's  "Concrete,  Plain  and 
Reinforced." 

t  These  may  be  obtained  by  addressing  The  Atlas  Portland  Cement  Company. 

t  The  maximum  size  of  stone  for  building  construction  is  customarily  limited  to  i  inch  or  i  J4  inch,  s'o 
that  the  concrete  may  be  carefully  placed  around  the  steel  and  into  the  corners  of  the  forms.  In  certain 
cases  K-inch  or  24-inch  stone  is  specified,  but  the  larger  size  is  better,  provided  it  can  be  properly  placed. 

25 


(as  determined  by  frequently  screening  samples)  is  uniform,  the  screening 
may  be  omitted  and  the  average  percentage  of  dust  allowed  for  in  measuring 
the  sand. 

Water. — The  water  shall  be  free  from  acids  or  strong  alkalies. 

Reinforcing  Steel.  | — *Steel  for  reinforcement  shall  have  an  "ultimate 
tensile  strength  of  55,000  to  65,000  pounds  per  square  inch,  an  elastic  limit 
of  not  less  than  one-half  the  ultimate  strength  (i.  e.,  not  less  than  27,000 
pounds)  and  a  minimum  elongation  in  8  inches  of  1,400,000  divided  by  the 
ultimate  strength  per  cent."  Metal  reinforcement  shall  be  of  such  shape  or 
so  anchored  as  suitably  to  assist  its  adhesion  to  the  concrete. 

PROPORTIONS  OF  MATERIALS. 

In  building  construction,  the  proportions  most  generally  adopted  are  i 
part  cement  to  2  parts  sand  to  4  parts  broken  stone  or  gravel  (this  being 
customarily  indicated  by  the  expression  1:2:4),  or  i  part  cement  to  2^ 
parts  sand  to  5  parts  broken  stone  or  gravel  (i.e.,  1:2^:5).  One  part  is  as- 
sumed to  be  equal  to  4  bags  of  cement,  or  one  barrel,  holding  3.8  cubic  feet; 
thus  proportions  1 12 14.  mean  one  barrel  (or  4  bags)  Portland  cement,  7.6 
cubic  feet  sand  measured  loose  and  15.2  cubic  feet  of  broken  stone  or  gravel 
measured  loose. 

On  a  small  job,  where  tests  cannot  be  made  so  economically  it  is  well  to 
be  conservative  and  require  proportions  1 12  14.  On  the  other  hand,  if  an  en- 
gineer is  constantly  present,  it  is  often  best  not  to  definitely  specify  the  re- 
lative amount  of  sand  to  stone,  but  to  permit  the  proportion  to  vary  with 
the  material ;  thus,  in  laying  the  concrete  if  there  is  an  excess  of  mortar  the 
quantity  of  sand  should  be  slightly  reduced  and  the  quantity  of  stone  corres- 
pondingly increased,  while  if  there  is  insufficient  mortar  to  cover  the  stone 
and  prevent  stone  pockets,  the  sand  may  be  increased  and  the  stone  decreased. 
The  proportion  of  cement  to  the  sum  of  the  parts  of  sand  and  stone  may  thus 
be  kept  constant. 

MACHINE  MIXING. 

*If  the  concrete  is  mixed  in  a  machine  mixer  a  machine  shall  be  selected 
into  which  the  materials,  including  the  water,  can  be  precisely  and  regularly 
proportioned,  and  which  will  produce  a  concrete  of  uniform  consistency  and 
color  with  the  stones  and  water  thoroughly  mixed  and  incorporated  with  the 
mortar. 

CONSISTENCY. 

For  building  construction  and  for  other  reinforced  concrete  work  it  is 
absolutely  necessary  that  the  concrete  shall  be  mixed  wet  enough  to  flow 

*   See  footnote  page  25. 

t   For  specifications  for  high  carbon  steel,  see  Taylor  &  Thompson's  "Concrete,  Plain  and  Reinforced," 
page  38. 

26 


around  and  thoroughly  imbed  the  steel,  but  it  must  be  no  wetter  than  is  re- 
quired to  attain  this  result.  If  mixed  too  dry,  air  voids  will  be  left  around 
the  stone,  and  stone  pockets  will  appear  on  the  face  of  the  concrete  after  re- 
moving the  forms.  If,  on  the  other  hand,  too  much  water  is  added,  the  sur- 
face may  have  a  similar  appearance  because  of  the  water  running  away  from 
the  stone. 

PLACING. 

^Concrete  shall  be  conveyed  to  place  in  such  a  manner  that  there  shall 
be  no  distinct  separation  of  the  different  ingredients,  or,  in  cases  where  such 
separation  inadvertently  occurs  the  concrete  shall  be  remixed  before  placing. 
Each  layer  in  which  the  concrete  is  placed  shall  be  of  such  thickness  that  it 
can  be  incorporated  with  the  one  previously  laid.  Concrete  shall  be  used  so 
soon  after  mixing  that  it  can  be  rammed  or  puddled  in  place  as  a  plastic 
homogeneous  mass.  Any  which  has  set  before  placing  shall  be  rejected. 
When  placing  fresh  concrete  upon  an  old  concrete  surface,  the  latter  shall  be 
cleaned  of  all  dirt  and  scum  or  laitance  and  thoroughly  wet.  Noticeable  voids 
or  stone  pockets  discovered  when  the  forms  are  removed  shall  be  immediately 
filled  with  mortar  mixed  in  the  same  proportions  as  the  mortar  in  the  con- 
crete. For  horizontal  joints  in  thin  walls,  or  in  walls  to  sustain  water  pres- 
sure, or  in  other  important  locations,  a  joint  of  mortar  in  proportions  de- 
signated by  the  engineer  may  be  required. 

SURFACES. 

The  proper  treatment  to  give  a  pleasing  appearance  to  exposed  surfaces 
is  one  of  the  most  difficult  problems  in  concrete  building  construction.  The 
surfaces  of  columns,  beams  and  the  under  sides  of  floors  can  be  made  suffi- 
ciently smooth  by  carefully  spading,  and  by  seeing  to  it  that  the  mortar  comes 
to  the  face  and  that  the  forms  are  tight  enough  to  prevent  the  mortar  running 
out. 

The  treatment  of  outside  surfaces  is  described  and  illustrated  in  Chapter 
XIV  on  Details  of  Construction,  and  the  methods  adopted  in  different  build- 
ings are  taken  up  in  the  descriptive  chapters  which  follow. 

FORMS. 

*The  lumber  for  the  forms  and  the  design  of  the  forms  shall  be  adapted 
to  the  structure  and  to  the  kind  of  surface  required  on  the  concrete.  For  ex- 
posed faces  the  surface  next  to  the  concrete  shall  be  dressed.  Forms  shall  be 
sufficiently  tight  to  prevent  loss  of  cement  or  mortar.  They  shall  be  thor- 
oughly braced  or  tied  together  so  that  the  pressure  of  the  concrete  or  the 
movement  of  men,  machinery  or  materials  shall  not  throw  them  out  of  place. 
Forms  shall  be  left  in  place  until  in  the  judgment  of  the  engineer  the  concrete 

*   See  footnote  page  25. 

27 


has  attained  sufficient  strength  to  resist  accidental  thrusts  and  permanent 
strains  which  may  come  upon  it.  Forms  shall  be  thoroughly  cleaned  before 
being  used  again. 

The  time  for  removal  of  forms  is  determined  by  the  weather  conditions 
and  actual  inspection  of  the  concrete.  The  following  approximate  rules  may 
be  followed  as  a  safe  guide  to  the  minimum  time  for  the  removal  of  forms  :* 

Walls  in  Mass  Work. — One  to  three  days,  or  until  the  concrete  will  bear 
pressure  of  the  thumb  without  indentation. 

Thin  Walls. — In  summer,  two  days;  in  cold  weather,  five  days. 

Slabs  up  to  Six  Feet  Span. — In  summer,  six  days;  in  cold  weather,  two 
weeks. 

Beams  and  Girders  and  Long  Span  Slabs. — In  summer,  ten  days  or  two 
weeks ;  in  cold  weather,  three  weeks  to  one  month.  If  shores  are  left  without 
disturbing  them,  the  time  of  removal  of  the  sheeting  in  summer  may  be  re- 
duced to  one  week. 

Column  Forms. — In  summer,  two  days;  in  cold  weather,  four  days,  pro- 
vided girders  are  shored  to  prevent  appreciable  weight  reaching  columns. 

A  very  important  exception  to  these  rules  applies  to  concrete  which  has 
been  frozen  after  placing,  or  has  been  maintained  at  a  temperature  just  above 
freezing.  In  such  cases  the  forms  must  be  left  in  place  until  after  warm 
weather  comes,  and  then  until  the  concrete  has  thoroughly  dried  out  and 
hardened. 

FOUNDATIONS. 

In  a  reinforced  concrete  building,  the  floor  loads  are  carried  by  the  slabs 
to  the  beams  and  girders,  and  thence  to  the  columns,  which  concentrate  the 
weight  upon  small  areas  of  ground.  The  footing  of  each  column  must  there- 
fore be  spread  over  a  large  enough  area  of  ground  so  as  not  to  over  compress 
the  soil  and  cause  appreciable  settlement. 

Mr.  George  B.  Francisj  suggests  the  following  loading  for  materials 
which  can  be  clearly  defined,  at  the  same  time  calling  attention  to  the  neces- 
sity for  varied  and  ample  experience  when  fixing  allowable  pressures  in  any 
particular  case : 

Ledge  rock,  36  tons  per  square  foot. 
Hard  pan,  8  tons  per  square  foot. 
Gravel,  5  tons  per  square  foot. 
Clean  sand,  4  tons  per  square  foot. 
Dry  clay,  3  tons  per  square  foot. 
Wet  clay,  2  tons  per  square  foot. 
Loam,  i  ton  per  square  foot. 

*  From  paper  on  "Forms'  for  Concrete  Construction,"  by  Sanford  E.  Thompson,  b'efore  National 
Association  of  Cement  Users,  1907. 

t  Taylor  &  Thompson's  "Concrete,  Plain  and   Reinforced,"   page  473. 

28 


To  illustrate  the  use  of  these  rules :  If  a  column  20  inches  square  carries 
a  load  from  above  of  80  tons,  the  footing  over  a  soil  of  dry  sand  must  cover 
an  area  of  -8T°-  =  20  square  feet;  that  is,  the  footing  must  be  about  4  feet  6 
inches  square. 

Not  only  must  the  area  be  calculated  to  distribute  the  load  over  a  proper 
area  of  soil,  but  the  thickness  of  the  footing  must  be  computed  so  as  to  pre- 
vent the  column  punching  or  shearing  through  it,  and  a  sufficient  amount  of 
reinforcing  steel  must  be  placed  in  the  bottom  of  the  concrete  footing  to 
prevent  its  buckling  and  breaking  from  the  concentrated  load  of  the  column. 
The  size  of  the  rods  is  calculated  from  the  bending  moment  produced  by  the 
upward  pressure  of  the  soil  against  the  projection  of  the  footing,  which  may 
be  assumed  to  be  a  beam  supported  upon  a  line  running  through  the  center 
of  the  column.  If,  as  is  customary,  the  footing  projects  in  both  directions  and 
the  rods  run  in  both  directions,  both  projections  may  be  taken  into  account  as 
resisting  the  pressure. 

In  certain  cases  where  a  very  large  footing  is  required,  especially  when 
the  footing  rests  on  piles,  stirrups  may  be  needed  to  resist  shear  or  diagonal 
tension,  as  in  an  ordinary  beam. 

Proportions  of  concrete  for  reinforced  footings  may  be  1 \2l/2  '.5,  i.  e.,  one 
part  Portland  cement  to  2^  parts  sand  to  5  parts  broken  stone  or  gravel,  or 
the  same  proportions  may  be  used  as  in  the  building  above  them. 

Foundations  in  dry  ground  which  do  not  require  reinforcement  and  sus- 
tain only  direct  compression  may  be  laid  in  proportions  of  1 13 :6  or  1 13 17. 
If  laid  under  water  the  concrete  should  not  be  leaner  than  1 i2l/2  15,  while  for 
sea  water  construction  a  mixture  at  least  as  rich  as  1 12 14  is  advisable,  with 
very  careful  testing  of  the  cement  and  aggregates. 

For  a  building  with  no  basement,  foundation  walls  between  the  columns 
are  unnecessary.  The  walls  may  be  started  just  below  the  surface  of  the 
ground,  and  each  wall  slab  will  form  of  itself  a  beam  supported  at  each  end 
by  the  column  foundation.  When  a  basement  is  included  in  the  design,  its 
wall  is  apt  to  act  as  a  retaining  wall  to  resist  the  pressure  of  earth,  and  it  may 
be  necessary  to  calculate  the  thickness  and  reinforcement  required  to  resist 
the  earth  pressure.  Frequently,  the  bottom  of  the  wall  is  held  by  the  base- 
ment floor,  and  the  top  by  the  first  floor  of  the  building.  In  this  case  it  may 
be  considered  as  a  slab  supported  at  the  bottom  and  top,  and  the  principal 
reinforcing  rods  should  be  vertical  and  placed  about  one  inch  from  the  interior 
face  of  the  wall.  If  there  is  no  support  at  the  top,  the  footing  may  be  en- 
larged by  careful  computation,  and  a  cantilever  design  made  with  the  princi- 
pal tension  rods  vertical  but  near  the  exterior  face  of  the  wall ;  or  the  vertical 
slab  may  be  supported  at  the  ends  by  columns  or  buttresses  of  proper  design, 
and  the  tension  rods,  computed  to  resist  the  earth  pressure,  run  horizontally 
near  the  interior  face. 

For  an  ordinary  cellar  wall  supported  at  bottom  and  top,  a  thickness  of 
8  inches  with  y%  inch  vertical  rods  about  one  foot  apart  will  be  strong  enough 
to  hold  the  earth,  but  it  is  best  to  actually  compute  the  thickness  and  rein- 

29 


forcement  for  any  given  case.  Even  if  the  principal  rods  are  vertical,  oc- 
casional horizontal  rods,  spaced  about  18  inches  or  2  feet  apart,  should  be 
placed  in  the  wall  to  tie  it  together  and  prevent  contraction  cracks. 

BASEMENT  FLOOR. 

The  earth  under  a  basement  floor  must  be  well  drained.  If  necessary, 
drains  of  tile  pipe  or  of  screened  gravel  or  stone  may  be  placed  in  trenches 
just  below  the  concrete,  or  the  entire  level  may  be  covered  with  cinders  or 
stone.  If  the  basement  is  below  tide  water  or  ground  water  level,  it  is  not 
safe  to  depend  upon  the  concrete  itself  being  water-tight,  and  a  layer  of  water 
proofing  consisting  of  four  to  six  layers  of  tarred  paper,  mopped  on,  may  be 
spread  on  the  concrete  and  carried  up  in  continuous  sheets  on  the  walls  to 
above  water  level,  and  the  whole  surface  covered  with  another  layer  of  con- 
crete. In  some  cases,  it  may  be  necessary  to  make  the  concrete  extra  thick, 
or  to  add  reinforcement,  to  resist  the  upward  pressure  of  the  water. 

For  a  basement  floor  in  dry  ground  a  3-inch  or  4-inch  thickness  of  ordi- 
nary 1 13 15  concrete, — that  is,  concrete  composed  of  i  part  Portland  cement  to 
3  parts  sand  to  5  parts  broken  stone  or  gravel, — may  be  laid  and  the  surface 
screeded  to  bring  it  to  the  required  level.  As  it  sets,  this  concrete  should  be 
troweled  just  as  the  wearing  surface  of  a  sidewalk  is  troweled,  but  without 
the  mortar  or  granolithic  finish  which  is  customarily  laid  upon  a  walk.  If  the 
floor  is  to  have  a  great  deal  of  wear  or  trucking,  the  usual  ^ -inch  or  i-inch 
layer  of  1 12  mortar  may  be  laid  upon  the  concrete  before  it  has  set,  forming  a 
part  of  the  total  thickness  of  4  inches ;  but  usually  this  is  an  unwarranted  ex- 
pense in  a  basement,  as  the  plain  concrete  will  give  as  good  service. 

It  is  well  in  any  case  to  divide  the  floor  into  blocks,  say,  8  or  10  feet 
square,  so  that  any  shrinkage  cracks  will  come  in  the  joints.  This  is  readily 
accomplished  by  laying  alternate  blocks,  and  then  filling  in  the  intermediate 
ones  the  next  day. 

DESIGN  OF  FLOOR  SYSTEM. 

LOADING. — In  designing  a  reinforced  concrete  building,  the  first  con- 
sideration is  the  loading  which  the  various  floors  must  sustain ;  in  other  words, 
the  strength  which  each  floor  must  have  to  support  the  weights  which  may 
confe  upon  it  under  all  conceivable  conditions.  In  a  factory  or  warehouse  it 
is  frequently  possible  to  accurately  calculate  the  maximum  weight  which  will 
come  upon  a  given  area  of  floor.  For  the  very  heaviest  loading  the  problem 
is  frequently  the  simplest,  since  the  heavy  weights  are  apt  to  be  due  to  the 
storage  of  merchandise  whose  weight  per  cubic  foot,  and  therefore  per  square 
foot  of  floor,  can  be  readily  calculated.  Sometimes  the  underside  of  the  floor 
must  support  tracks  which  carry  certain  definite  weights,  and  the  beams  or 
girders  must  be  calculated  for  these  concentrated  loads  in  addition  to  the 
uniform  loads  upon  the  floor. 

In  computing  the  strength  of  the  floor  system,  the  weight  of  the  concrete 

30 


itself  must  always  be  allowed  for.  In  very  long  spans  the  concrete  frequently 
weighs  more  than  the  load  which  will  be  placed  upon  it. 

In  many  cases  the  loading  must  be  assumed  without  actual  computation. 
A  maximum  load  must  frequently  be  selected  to  support  machinery  whose 
weight  is  slight  but  whose  vibrations  require  a  stiff  floor  system. 

The  various  conditions  met  with  in  warehouse  or  factory  construction 
may  thus  necessitate  loadings  varying  from  100  to  500  pounds  per  square 
foot  of  floor  area,  very  wide  limits  and  yet  not  more  than  occur  in  practice. 
As  a  guide  to  the  selection  of  floor  loads,  the  following  values  are  suggested : 

OfBce  floors    100  pounds  per  square  foot 

Light  running  machinery    150  pounds  per  square  foot 

Medium  heavy  machinery    200  pounds  per  square  foot 

Heavy  machinery   250  pounds  per  square  foot 

Storage  of  parts  or  finished  products,  de- 
pending upon  actual  calculated  loads, 

150  to  500  pounds  per  square  foot 

When  the  loads  are  apt  to  occur  only  over  a  part  of  the  floor,  the  slabs 
and  beams  are  calculated  for  the  full  load,  and  when  computing  the  girders 
and  columns  a  slightly  smaller  load  is  sometimes  used.  For  example,  if  the 
slabs  and  beams  are  figured  for  200  pounds  per  square  foot  of  floor  area,  it 
might  be  assumed  that  the  whole  of  the  total  area  supported  by  a  girder  or 
column  would  never  be  loaded  at  once,  and  the  load  per  square  foot  actually 
reaching  the  girder  and  column  at  any  one  time  would  be  therefore  not  more 
than  150  pounds  per  square  foot  of  floor  area. 

LAYOUT. — The  general  layout  of  the  beams  and  girders  and  columns 
depends  upon  the  loading,  the  uses  to  which  the  building  is  to  be  put,  and  the 
ground  area.  Frequently  in  a  large  building,  it  will  be  worth  while  to  require 
the  engineer  to  make  several  comparative  estimates  with  different  spacings 
of  columns  and  sizes  of  panels,  so  as  to  determine  that  which  is  most  economi- 
cal consistent  with  the  floor  area  required  for  the  machinery. 

Common  spacings  of  columns  in  a  reinforced  concrete  building  are  from 
12  feet  to  20  feet.  Longer  spans  are  not  usually  so  economical,  but  may  fre- 
quently be  necessary  to  give  the  floor  space  required  for  machinery  or  storage. 
Several  of  the  buildings  described  in  the  chapters  which  follow  are  designed 
for  long  spans,  but  it  will  be  noticed  that  very  heavy  beams  and  girders  are 
required  for  them. 

Taking  a  general  case,  if  the  spacing  of  the  columns  is  20  feet  each  way, 
the  columns  are  connected  by  girders  running  in  one  direction,  usually  the 
long  way  of  the  building,  and  into  these  girders  run  beams  spaced  6  feet  to  8 
feet  apart.  Other  arrangements  will  suggest  themselves  from  the  descriptive 
chapters  which  follow. 


FLOOR  SLABS. — The  thickness  and  reinforcement  of  the  floor  slabs 
is  determined  by  the  distance  beween  the  beams,  and  by  the  loading  which 
will  come  upon  them.  The  most  usual  thicknesses  are  3/2  inches  to  5  inches, 
with  reinforcement  calculated  from  the  bending  moment  produced  by  the 
loads.  An  economical  quantity  of  steel  is  apt  to  be  from  0.8  per  cent,  to  i  per 
cent,  of  the  sectional  area  of  the  slab  above  the  steel. 

A  few  rods  are  usually  placed  at  right  angles  to  the  main  bearing  rods 
of  the  slab  to  assist  in  preventing  contraction  cracks,  and  these  also  add  to 
the  strength  of  the  slab. 

In  a  factory  or  warehouse  the  most  economical  floor  surface  is  generally 
a  granolithic  finish,  consisting  of  a  layer  of  1 12  mortar  about  three-quarter 
inch  thick,  spread  upon  the  surface  of  the  concrete  slab  before  it  has  begun 
to  set,  and  troweled  to  a  hard  finish  just  like  a  concrete  sidewalk. 

Machines  are  readily  bolted  to  the  concrete  by  drilling  small  holes  in  the 
concrete  at  the  proper  points  for  the  standards  and  grouting  the  lag  screws  in 
place,  or  else  bolting  them  through  the  slab. 

If  for  any  reason  a  wood  floor  is  required,  stringers  may  be  laid  upon  the 
top  of  the  concrete  and  spaces  left  between  them  or  filled  with  cinders  or 
with  cinder  concrete. 

BEAMS  AND  GIRDERS. — As  already  indicated,  the  sizes  and  rein- 
forcement of  the  beams  and  girders  must  be  accurately  computed  by  one  who 
thoroughly  understands  the  theories  involved  in  reinforced  concrete  design. 
Even  if  tables  are  used  the  designer  must  have  a  knowledge  of  mechanics  and 
of  the  way  in  which  the  stresses  act. 

It  is  a  simple  matter  to  determine  the  amount  of  steel  required  in  the  bot- 
tom of  the  beam  to  sustain  the  pull  due  to  a  given  loading,  but  while  this  is 
an  important  determination  it  is  by  no  means  the  only  one. 

The  weak  points  in  reinforced  concrete  structures  are  not  usually  due  to 
insufficient  steel  for  tension,  but  more  often  to  an  ignorance  of  other  smaller 
details  not  less  important.  It  is  thus  absolutely  dangerous,  and  in  fact  crimi- 
nal, for  a  novice  to  design  or  pass  upon  drawings  for  a  reinforced  concrete 
structure. 

The  design  of  reinforced  concrete  beams  and  girders  involves  the  follow- 
ing studies : 

(1)  The  bending  moment  due  to  the  live  and  dead  loads,  this  involving 
the  selection  of  the  proper  formula  for  the  computation. 

(2)  Dimensions  of  beams  which  will  prevent  an  excessive  compression 
of  the  concrete  in  the  top  and  which  will  give  the  depth  and  width  which  is 
otherwise  most  economical. 

(3)  Number  and  size  of  rods  to  sustain  tension  in  the  bottom  of  the 
beam. 

(4)  Shear  or  diagonal  tension  in  the  concrete. 

(5)  Value  of  bent-up  rods  to  resist  shear  or  diagonal  tension. 

32 


(6)  Stirrups  to  supplement  the  bent-up  rods  in  assisting  to  resist  the 
shear  or  diagonal  tension. 

(7)  Steel  over  the  supports  to  take  the  tension  due  to  negative  bending 
moment. 

(8)  Concrete  in  compression  at  the  bottom  of  the  beam  near  the  sup- 
ports due  to  negative  bending  moment. 

(9)  Horizontal  shear  under  flange  of  slab. 

(10)     Shear  on  vertical  planes  between  beams  and  flanges, 
(u)     Distance  apart  of  rods  to  resist  splitting. 

(12)  Length  of  rods  to  prevent  slipping. 

(13)  End  connections  at  wall. 

Although  it  is  not  the  province  of  this  book  to  go  into  the  mathematical 
treatment  of  these  various  points,  many  of  them  are  as  yet  so  inadequately 
treated  in  literature  on  the  subject  that  it  will  be  advisable  to  touch  upon  them 
in  a  general  way. 

BENDING  MOMENT.— The  first  important  computation  for  an  en- 
gineer to  make  is  the  determination  of  the  bending  moment.  In  a  beam  which 
is  merely  supported  at  the  ends  like  a  steel  beam  or  a  timber  girder  resting 
upon  columns,  the  calculation  is  very  simple,  and  can  be  readily  made  by 
drawing  a  load  diagram,  or  in  the  simple  case  of  a  uniformly  distributed  load 
by  using  the  formula 

M=^WL  (i) 

in  which 

M  =  =  bending  moment  in  inch  pounds. 

W  =  =  total  load  in  pounds  supported  by  the  beam  or  girder  (including 
the  dead  load). 

L  =  =  length  of  span  of  beam  or  girder  in  inches. 

When  a  beam  is  continuous  or  is  more  or  less  fixed  at  the  ends,  as  is  the 
case  in  reinforced  concrete  construction,  where  the  entire  floor  system  is  laid 
as  one  unit,  the  conditions  are  changed,  the  stress  in  the  center  of  the  beam 
is  less,  and  there  is  also  a  reverse  action,  termed  the  negative  bending  moment, 
at  the  supports. 

It  is,  therefore,  conservative  practice  to  use  in  general  for  slabs,  and  for 
beams  and  girders  which  are  built  into  each  other  or  into  heavy  columns,  the 
formula 

M  =  i/ioWL  (2) 

For  the  end  spans,  that  is,  for  beams  and  girders  running  into  a  wall,  formula 
(i)  is  generally  used  instead. 

These  values  for  the  bending  moment,  as  stated,  are  conservative  and 
eventually  it  will  probably  be  considered  safe  to  slightly  increase  them. 

The  negative  bending  moment  at  the  end  of  the  beams  must  be  provided 
for  by  steel  rods  carried  over  the  top  of  the  support  for  tension,  and  by  a 
sufficient  quantity  of  concrete  at  the  bottom  of  the  beam  near  the  support  to 

33 


take  the  compression.  Using  formula  (i)  or  (2)  for  the  design  at  the  center 
gives  a  very  stiff  beam  so  that  for  the  negative  moment  at  the  ends  it  is  safe 
to  use 

__M=  1/12  WL 

Since  the  pull  in  the  bottom  of  the  beam  decreases  toward  the  supports 
a  part  of  the  tension  rods  may  be  bent  up  on  an  incline  from  about  one-quarter 
points  in  the  beam,  if  the  load  is  uniformly  distributed,  and  pass  horizontally 
through  the  top  of  the  beam  at  the  supports.  The  rods  must  extend  over  the 
supports  for  a  sufficient  distance  to  receive  the  compressive  stress  there,  or 
must  be  firmly  connected  with  corresponding  rods  in  the  adjacent  bay.  The 
total  steel  in  the  top  must  be  sufficient  to  resist  the  tension  due  to  the  negative 
moment. 

In  slabs  it  is  good  practice  to  bend  up  all  of  the  rods  at  the  quarter  points 
toward  the  supports. 

STEEL. — City  building  laws  are  apt  to  limit  the  tension  in  steel  to  16,000 
pounds  per  square  inch.  Many  engineers  adopt  the  value,  slightly  more  con- 
servative and  therefore  preferable,  of  14,000  pounds  per  square  inch. 

CONCRETE. — If  the  concrete  is  made  of  first-class  materials  mixed  not 
leaner  than  i  part  cement  to  2  parts  sand  to  4  parts  stone,  so  as  to  have  a 
compressive  strength  of  at  least  2,000  pounds  per  square  inch  at  the  age  of 
28  days,  a  value  as  high  as  600  pounds  per  square  inch  for  the  extreme  fiber 
compression  in  beams  and  slabs  may  be  used  with  safety,  provided  the  com- 
putation is  based  on  what  is  termed  the  straight  line  distribution  of  stress, 
and  the  ratio  of  the  modulus  of  elasticity  of  steel  to  concrete  is  taken  at  15. 
To  guard  against  the  possibility  of  poor  workmanship,  building  departments 
frequently  fix  a  limit  of  500  pounds  per  square  inch. 

In  computing  the  compression,  the  beam  is  usually  considered  of  T-sec- 
tion,  that  is,  the  slab  for  a  certain  distance  on  each  side  of  the  beam  is  as- 
sumed to  act  as  part  of  the  beam.  The  width  of  slab  to  use  in  computing  the 
beam  is  usually  taken  from  one-fifth  to  one-third  the  span  of  the  beam,  and 
not  more  than  two-thirds  the  distance  between  beams.  In  order  to  take  ad- 
vantage of  the  strength  of  the  slab,  it  is  absolutely  necessary  that  the  concrete 
be  laid  in  the  slabs  at  the  same  time  as  in  the  beams,  so  as  to  prevent  any 
joint  between  them.  The  disregard  of  this  important  rule  has  contributed  to 
more  than  one  failure  of  reinforced  concrete. 

STIRRUPS. — Besides  the  ordinary  compression  and  pull  in  a  beam, 
there  are  secondary  stresses  of  shear  or  diagonal  tension,  which,  if  not  pro- 
vided for,  will  produce  diagonal  cracks.  These  will  run  in  a  general  direction 
from  the  bottom  of  the  beam  near  the  supports  on  an  incline  toward  the  top 
of  the  beam,  and  may  cause  the  beam  to  fail.  To  prevent  this  cracking,  unless 
the  beam  is  so  wide  that  the  concrete  can  take  the  whole  of  the  stress  without 
exceeding  60  pounds  per  square  inch  in  shear,  vertical  or  inclined  steel  bars, 

34 


of  sizes  accurately  computed,  must  be  placed.  The  bent-up  tension  rods 
take  care  of  a  part  of  this  shear,  or  diagonal  tension,  but  if  these  are  not  suffi- 
cient, stirrups,  which  are  usually  made  in  the  form  of  a  U,  must  be  inserted 
at  the  proper  locations  to  take  the  remainder. 

COLUMNS. 

The  most  important  of  all  the  members  of  the  building  are  the  columns, 
for  if  a  column  fails  the  entire  building  is  liable  to  go  down. 

If  columns  as  ordinarily  built  in  building  construction  are  made  of  1:2:4 
proportions,  it  is  safe  in  an  ordinary  building  to  allow  a  direct  compressive 
strength  of  450  pounds  per  square  inch,  provided  the  columns  are  at  least  12 
inches  square.  A  customary  manner  of  designing  is  to  figure  the  entire  com- 
pression upon  the  concrete  to  the  full  size  of  the  column,  but  to  place  four  or 
possibly  six  rods  of  5/£-inch  or  .vj-inch  diameter  near  the  corners  or  sides  of 
the  column,  with  ]^-mch  wire  loops  around  these  rods  at  occasional  intervals 
in  the  height,  say,  from  8  to  12  inches  apart. 

Vertical  steel-rods  of  larger  size  may  be  introduced  when  it  is  necessary 
to  decrease  the  size  of  the  columns.  These  may  be  computed  to  bear  a  por- 
tion of  the  compressive  load,  but  they  cannot  be  figured  at  their  full  safe 
value  of  16,000  pounds  per  square  inch  because  they  have  a  different  modulus 
of  elasticity  and  compressive  strength  from  concrete  and  can  only  shorten  the 
same  amount  as  the  concrete.  Under  ordinary  circumstances,  therefore,  they 
cannot  be  assumed  to  bear  more  than  the  safe  compressive  stress  in  the  con- 
crete times  the  ratio  of  elasticity  of  steel  to  concrete,  or  about  7,000  pounds 
per  square  inch.  Because  of  this  small  amount  of  compression  which  they 
can  bear,  it  is  always  cheaper  to  enlarge  the  column  rather  than  to  insert 
steel  of  larger  diameter  to  assist  in  taking  the  load. 

Another  means  of  increasing  the  strength  of  the  column  is  to  use  a  richer 
mixture.  This  is  legitimate  provided  the  same  mixture  is  carried  up  through 
the  floor  system  at  the  column  so  that  there  will  be  no  weak  places.  By 
using  proportions  1:1:3  a  safe  working  compression  in  the  concrete  of  700 
pounds  per  square  inch  may  be  adopted. 

Hooped  columns,  that  is,  columns  reinforced  with  bands  placed  near  to- 
gether or  with  spirals,  are  frequently  adopted  to  reduce  the  size  of  the  column. 
It  is  a  serious  question  in  the  minds  of  conservative  engineers  as  to  whether 
it  is  good  practice  to  assume  that  a  large  proportion  of  the  load  can  be  borne 
by  such  hoops.  Although  tests  have  shown  that  hooped  columns  have  a  high 
ultimate  strength,  these  same  tests  prove  that  the  concrete  within  the  hoops 
is  overstrained  before  the  hoops  begin  to  take  any  of  the  tension  which  must 
reach  them  in  order  to  strengthen  the  columns. 

Composite  columns,  which  are  virtually  steel  columns  surrounded  by 
concrete,  have  been  used  in  a  number  of  buildings.  An  instance  of  this  is  the 
Ketterlinus  building,  described  in  Chapter  V.  This  construction,  although 

35 


more  expensive  than  plain  concrete,  is  advantageous  where  the  floor  space  is 
so  valuable  that  the  dimensions  of  the  columns  must  be  kept  small. 

WALLS. 

The  walls  of  reinforced  concrete  factories  are  sometimes  built  up  with 
the  columns,  but  it  is  generally  considered  more  economical  to  erect  the  skele- 
ton structure  and  fill  in  the  wall  panels,  as  described  in  Chapters  VI  and  IX. 

Slots  in  the  columns  are  made  by  nailing  a  strip  on  the  inside  of  the 
column  forms.  In  this  way  the  panels  are  mortised  into  the  columns. 

Ordinary  concrete  walls  require  light  reinforcement  to  prevent  shrinkage 
and  give  them  stiffness  while  setting.  All  that  is  required  for,  say,  a  4-inch 
or  6-inch  wall  are  ^-inch  rods  spaced  from  12  to  24  inches  apart,  accord- 
ing to  the  size  and  importance  of  the  wall.  At  window  and  door  openings 
a  larger  amount  of  reinforcement  is  of  course  necessary,  and  in  these  cases 
the  amount  of  steel  must  be  calculated  just  as  though  the  lintels  were  re- 
inforced concrete  beams. 

ROOFS. 

Reinforced  concrete  roofs  are  designed  like  floors.  A  roof  load  commonly 
assumed  in  temperate  climates,  to  provide  for  roof  covering,  snow  and  wind 
pressure,  is  40  pounds  per  square  foot,  in  addition  to  the  weight  of  the  concrete 
itself. 

It  is  not  safe  to  assume  that  the  concrete  roof  of  itself  will  be  water-tight 
unless  special  provision  is  made  in  the  construction.  Although  tanks  and 
walls  can  readily  be  made  to  hold  water,  a  roof  is  under  extraordinarily  dis- 
advantageous conditions  because  of  the  rays  of  the  sun.  Usually,  therefore, 
a  tar  and  gravel  or  other  form  of  roof  covering  must  be  provided. 

CONSTRUCTION. 

The  details  of  construction  are  treated  at  length  for  individual  buildings 
in  the  chapters  which  follow.  Chapter  XIV  also  takes  up  many  special  points 
and  treats  as  well  of  different  methods  of  reinforcing. 

A  reinforced  concrete  building  must  have  careful  inspection  while  in 
process  of  erection,  the  special  points  to  be  observed  being: 

(1)  Exact  proportioning  of  materials. 

(2)  Placing  the  concrete  so  as  to  prevent  separation  of  ingredients. 

(3)  Placing  concrete  to  avoid  joints  except  where  called  for. 

(4)  Exact  placing  and  imbedding  of  the  reinforcement. 

(5)  Proper  securing  of  the  forms. 

(6)  Maintenance  of  the  forms  in  position  until  the  concrete  is  sufficiently 
strong. 


CHAPTER  III. 


CONCRETE  AGGREGATES.* 

The  term  "aggregate"  includes  not  only  the  stone,  but  also  the  sand  which 
is  mixed  with  cement  to  form  either  concrete  or  mortar ;  in  other  words,  it  is 
the  entire  inert  mineral  material.  This  definition,  now  generally  accepted, 
has  replaced  the  one  restricting  the  term  to  the  coarse  aggregate  alone.  It 
is  the  object  of  this  chapter  to  enumerate  the  general  principles  which  should 
be  followed  in  the  selection  of  sand  and  stone  for  mortar  and  concrete,  and 
to  describe  briefly  the  method  of  testing  aggregates  and  determining  propor- 
tions which  the  author  has  found  to  give  good  results  in  practice. 

At  the  outset,  it  may  be  said  that  a  concrete  of  fair  quality,  if  rich  enough 
in  cement,  can  be  made  with  nearly  any  kind  of  mineral  aggregate,  but  there 
is,  nevertheless,  a  wide  variation  in  the  results  produced.  For  the  fine  aggre- 
gate, sand,  broken  stone,  screenings,  pulverized  slag  or  the  fine  material  from 
cinders  may  be  used  separately  or  in  combination  with  each  other.  For  the 
coarse  aggregate,  broken  stone,  gravel,  screened  gravel  slag,  crushed  lava, 
shells,  broken  brick,  or  mixtures  of  any  of  these  may  be  employed.  However, 
the  very  fact  of  the  adaptability  of  concrete  to  so  wide  a  range  of  materials, 
every  one  of  which  really  consists  of  a  large  class  varying  in  size,  shape  and 
composition,  tends  to  blind  one  to  the  economies  which  often  may  be  effected 
and  the  improvement  in  quality  which  almost  always  will  result  by  a  careful 
selection  and  proportioning  of  the  aggregates. 

In  many  cases,  especially  where  the  cost  of  Portland  cement  is  low,  it 
may  be  cheaper  to  use  whatever  materials  are  nearest  at  hand,  and  insure  the 
quality  of  the  concrete  or  mortar  by  making  it  excessively  rich  in  cement.  If 
the  structure  is  small  and  of  little  importance  this  course  is  properly  followed, 
but,  on  the  other  hand,  if  a  large  amount  of  concrete  is  to  be  laid,  and  es- 
pecially if  the  process  is  to  be  carried  on  in  a  factory,  as  in  concrete  block 
manufacture,  it  pays  from  the  standpoints  of  both  quality  and  economy  to 
use  great  care  in  the  selection  of  the  aggregates,  as  well  as  of  the  cement,  and 
to  provide  means  for  maintaining  uniformity. 

To  illustrate  the  variation  which  different  aggregates  may  produce  even 
when  they  are  mixed  with  cement  in  the  same  proportions,  the  author  has 
selected  a  few  comparative  tests  of  mortar  and  concrete. 

*   Read   by    the    author   before    the    National    Association    of    Cement    Users,    June,    1906. 

37 


EFFECT  OF  DIFFERENT  AGGREGATES   UPON  THE  STRENGTH 
OF  MORTAR  AND   CONCRETE. 

Tests  by  Mr.  Rene  Feret,*  of  France,  with  mortar  made  from  different 
natural  sands  show  a  surprising  variation  in  strength,  which  is  evidently  due 
simply  to  the  fineness  of  the  sand  of  which  the  different  specimens  are  com- 
posed. Selecting  from  his  results  proportions  1 12^2  by  weight — that  is,  i 
part  cement  to  2^  parts  sand — and  converting  his  results  at  the  age  of  five 
months  from  French  units  to  pounds  per  square  inch,  the  average  tensile 
strength  of  Portland  cement  mortar  made  with  coarse  sand  is  421  pounds  per 
square  inch,  with  medium  sand  368  pounds  per  square  inch,  and  with  fine 
sand  302  pounds  per  square  inch.  In  the  crushing  strength,  usually  the  most 
important  consideration,  the  difference  is  even  more  marked.  In  round  num- 
bers, at  the  age  of  five  months  the  mortar  of  coarse  sand  gave  5,200  pounds 
per  square  inch;  of  the  medium  sand,  3,400  pounds  per  square  inch,  and  of 
the  fine  sand  1,900  pounds  per  square  inch.  Note  that  the  different  sands 
were  not  artificially  prepared,  but  were  taken  from  the  natural  bank  and 
correspond  to  those  which  every  day  are  being  used  for  concrete  and  mortar. 

The  effect  of  different  mixtures  of  the  same  kind  of  material  is  shown  by 
tests  made  by  the  author  in  19054  By  varying  the  sizes  of  the  particles  of 
the  aggregates,  but  using  in  all  cases  stone  from  the  same  ledge  and  the  same 
proportion  of  cement  to  total  aggregate  by  weight,  namely,  i  :g  (or  approxi- 
mately 1:3:6),  it  was  found  possible  to  make  specimens  the  resulting 
strengths  of  some  of  which  were  two  and  a  half  times  the  strength  of  others. 

The  effect  of  the  hardness  or  strength  of  the  stone  used  for  the  coarse 
aggregate  is  shown  in  tests  of  George  W.  Rafter,  J  which,  for  proportions 
about  1 126,3/2,  gave  50  per  cent,  greater  compressive  strength  of  concrete  where 
the  coarse  aggregate  was  a  hard  sandstone  than  with  similar  proportions 
where  a  shale  was  substituted.  In  some  of  his  tests  the  harder  stone  gave  a 
concrete  even  double  the  strength  of  the  concrete  with  softer  stone. 

GENERAL  PRINCIPLES  FOR  SELECTING  STONE. 

The  quality  of  concrete  is  affected  by  the  hardness  of  the  stone,  the  shape 
of  the  particles,  the  maximum  size  of  the  particles  and  the  relative  sizes  of 
the  particles. 

If  broken  stone  is  used,  and  there  is  an  opportunity  for  choice,  the  best 
is  that  which  is  hard;  with  cubical  fracture;  with  particles  whose  maximum 
size  is  as  large  as  can  be  handled  in  the  work ;  with  the  particles  smaller  than, 
sav»  YA  inch,  screened  out  to  be  used  as  sand;  and  with  the  sizes  of  the  re- 
maining coarse  stone  varying  from  small  to  large,  the  coarsest  predominat- 
ing. 

If  gravel  is  used  it  must  be  clean.  The  maximum  size  of  particles  should 
be  as  large  as  can  be  handled  in  the  work ;  grains  below,  say,  ^  inch,  should 

*  Taylor  &  Thompson's  "Concrete,  Plain  and   Reinforced,"   page    136. 
t    Proceeding  American   Society  of  Civil   Engineers,  March,    1907. 
t    Second  Report  on  Genesee  River   Storage  Project,    1894. 

38 


be  screened  out  to  be  used  as  sand,  and  the  size  of  the  stone  should  vary, 
with  the  coarsest  predominating. 

As  already  stated,  the  size  of  the  coarsest  particles  of  stone  should  be  as 
large  as  can  be  handled  in  the  work.  This  is  because  the  strength  of  the  con- 
crete is  thereby  increased  and  a  leaner  mixture  can  be  used  than  with  small 
stone.  In  mass  concrete  the  stones  if  too  large  are  liable  to  separate  from  the 
mortar  unless  placed  by  hand  or  derrick,  as  in  rubble  concrete,  and  a  practical 
maximum  size  is  2^  or  3  inches.  In  thin  walls,  floors  and  other  reinforced 
construction,  a  i-inch  maximum  size  is  generally  as  large  as  can  be  easily 
worked  between  the  steel.  In  some  cases  where  the  walls  are  very  thin,  say 
3  or  4  inches,  a  ^4~mch  maximum  size  is  more  convenient  to  handle. 

It  is  a  little  more  trouble  but  almost  always  best  to  screen  out  the  sand 
from  gravel  or  the  fine  material  from  crusher  stone,  and  then  remix  it  in  the 
proportions  required  by  the  specifications,  for  otherwise  the  proportions  will 
vary  at  different  points,  and  one  must  use  and  pay  for  an  excess  of  cement 
to  balance  the  lack  of  uniformity. 

If  the  gravel  is  used,  it  is  absolutely  essential  that  it  shall  be  clean,  be- 
cause if  clay  or  loam  adheres  to  the  particles,  the  adhesion  of  the  cement  will 
be  destroyed  or  weakened.  Tests  of  the  Boston  Transit  Commission*  give 
an  average  unit  transverse  strength  of  605  pounds  per  square  inch  for  con- 
crete made  with  clean  gravel  as  against  446  pounds  per  square  inch  when 
made  with  dirty  gravel. 

COMPARATIVE  VALUES  OF  DIFFERENT  STONE, 

Different  stones  of  the  same  class  vary  so  widely  in  texture  and  strength 
that  it  is  impossible  to  give  their  exact  comparative  values  for  concrete.  A 
comparison  by  the  author  of  a  large  number  of  tests  of  concrete  made  with 
different  kinds  of  stone  indicates  that  the  value  of  a  broken  stone  for  concrete 
is  largely  governed  by  the  actual  strength  of  the  stone  itself,  the  hardest  stone 
producing  the  strongest  concrete.  This  forms  a  valuable  guide  for  comparing 
different  stones.  Comparative  tests  indicate  that  different  stones  in  order 
of  their  value  for  concrete  are  approximately  as  follows:  (i)  Trap,  (2)  gra- 
nite* (3)  gravel,  (4)  marble,  (5)  limestone,  (6)  slag,  (7)  sandstone,  (8)  slate, 
(9)  shale,  (10)  cinders.  Although  as  stated  above,  the  wide  difference  in  the 
quality  of  the  stone  of  any  class  makes  accurate  comparisons  impossible — 
and  this  difficulty  is  increased  by  the  fact  that  the  proportions  and  age  of  the 
specimens  affect  their  relative  value — an  approximate  estimate  drawn  from 
actual  tests  gives  the  value  for  concrete  of  good  quality  sandstone  as  not 
more  than  three-fourths  the  value  of  trap,  and  the  value  of  slate  as  less  than 
half  that  of  trap.  Good  cinders  nearly  equal  slate  and  shale  in  the  strength 
of  concrete  made  with  them. 

The  hardness  of  the  stone  grows  in  importance  with  the  age  of  the  con- 
crete. Thus  gravel  concrete,  because  of  the  rounded  surfaces,  at  the  age  of 
one  month  may  be  weaker  than  a  concrete  made  with  comparatively  soft 

*  Seventh   Report  of  Boston  Transit   Commission,   1901,  page  39. 

39 


broken  stone ;  but  at  the  age  of  one  year  it  may  surpass  in  strength  the  broken 
stone  concrete,  because  as  the  cement  becomes  hard,  there  is  greater  tendency 
for  the  stones  themselves  to  shear  through,  and  the  hardness  of  the  gravel 
stones  thus  comes  into  play.  Gravel  makes  a  dense  mixture,  and  if  much 
cheaper  than  broken  stone,  can  usually  be  substituted  for  it. 

A  flat  grained  material  packs  less  closely  and  generally  is  inferior  to 
stone  of  cubical  fracture. 

GENERAL  PRINCIPLES  FOR  SELECTING  SAND. 

The  only  characteristics  of  sand  which  need  be  considered  are  the  coarse- 
ness of  its  grains  and  its  cleanness.  These  qualities  affect  the  density  of  the 
mortar  produced,  and  therefore  the  test  of  the  volume  of  mortar,  or  "yield" 
determines  which  of  two  or  more  sands  is  best  graded.  The  "yield"  or 
"volumetric"  test  is  considered  by  the  author  of  greater  value  for  quick  re- 
sults than  all  others  put  together.  The  methods  of  employing  it  are  described 
farther  along  in  the  paper. 

The  best  sand  is  that  which  produces  the  smallest  volume  of  plastic 
mortar  when  mixed  with  cement  in  the  required  proportions  by  weight. 

A  high  weight  of  sand  and  a  corresponding  low  percentage  of  voids  are 
indications  of  coarseness  and  good  grading  of  particles;  but  because  of  the 
impossibility  of  establishing  uniformity  in  weighing  or  measuring,  they  are 
merely  general  guides  which  cannot  under  any  conditions  be  taken  as  positive 
indications  of  true  relative  values.  The  various  characteristics  of  sands  are 
separately  considered  in  the  following  paragraphs : 

WEIGHT  OF  SAND. — A  heavy  sand  is  generally  denser,  and  there- 
fore better  than  a  light  sand.  However,  this  is  not  a  positive  sign  of  worth, 
because  the  difference  in  moisture  may  affect  the  weight  by  20  per  cent.,  and 
when  weighed  dry  the  results  are  not  comparable  for  mortars,  since  fine  sand 
takes  more  water  than  coarse. 

As  an  illustration  of  the  variation  in  weight  of  natural  sands  having 
different  moisture,  the  author  found  that  the  weight  per  cubic  foot  of  Cowe 
Bay  sand,  which  dry  averaged  103  pounds,  when  placed  out  of  doors  and  after 
a  rain  shoveled  into  a  measure  and  weighed  in  exactly  the  same  way  (al- 
though it  was  allowed  to  drain  for  two  days)  averaged  83  pounds. 

VOIDS  IN  SAND.— The  voids,  like  the  weight,  are  so  variable  in  the 
same  sand,  because  of  different  percentages  of  moisture  and  different  methods 
of  handling,  that  their  determination  is  of  but  slight  value.  In  the  Cowe  Bay 
sand  just  mentioned,  the  voids  were  38  per  cent,  in  the  sand,  dry,  and  52  per 
cent,  in  the  same  sand,  moist. 

Because  of  such  discrepancies,  the  author  prefers  to  mix  the  sand  with 
the  cement  and  water,  and  determine  the  voids  in  the  fresh  mortar,  as  de- 
scribed later.  This  gives  a  true  comparison  of  different  sands,  since  with  the 

40 


same  percentage  of  cement,  the  mortar  having  the  lowest  air  plus  water  voids 
is  the  strongest. 

COARSENESS  OF  SAND.— A  coarse  sand  produces  the  densest,  and, 
therefore,  the  strongest  mortar  or  concrete.  A  sufficient  quantity  of  fine 
grains  is  valuable  to  grade  down  and  reduce  the  size  of  the  voids,  but  in 
ordinary  natural  material,  either  sand  or  screenings,  there  will  be  found  suffi- 
cient fine  material  for  ordinary  proportions,  such  as  1:1,  1:2,  or  i:2l/>.  For 
leaner  proportions,  such  as  1 14  or  i  -.5,  and  sometimes  1 13,  an  addition  of  fine 
particles  will  be  found  advantageous  to  assist  the  cement  in  filling  the  voids. 
A  dirty  sand,  that  is,  one  containing  fine  clay  or  other  mineral  matter,  up  to 
say,  10  per  cent.,  is  actually  found  by  tests  to  be  better  than  a  clean  sand  for 
lean  mortars. 

For  water-tight  work  it  is  probable  that  a  larger  proportion  of  very  fine 
grains  may  be  employed  than  for  the  best  results  in  strength.  This  is  a 
question,  however,  which  has  not  yet  been  thoroughly  investigated. 

Feret's  rule  for  sand  to  produce  the  densest  mortar  is  to  proportion  the 
coarse  grains  as  double  the  fine,  including  the  cement,  with  no  grains  of  in- 
termediate size.  There  is  difficulty  in  an  exact  practical  application  of  this 
rule,  but  it  indicates  the  trend  to  be  followed  in  seeking  maximum  density 
and  strength. 

CLEANNESS  OF  SAND.— An  excess  of  fine  material  or  dirt,  as  has 
just  been  noted,  weakens  a  mortar  which  is  rich  in  cement.  It  may  also 
seriously  retard  its  setting.  The  author's  attention  was  recently  called  to  a 
concrete  lining,  one  portion  of  which  failed  to  set  hard  for  several  weeks, 
although  the  same  cement  was  used  as  on  adjacent  portions  of  the  work. 
The  difficulty  proved  to  be  due  entirely  to  the  fact  that  the  contractor  sub- 
stituted, in  this  place,  a  very  fine  sand,  the  regular  material  happening  to  run 
low. 

SHARPNESS  OF  SAND.— Notice  that  the  quality  of  sharpness  has  not 
been  mentioned  among  the  essential  characteristics  of  sand.  This  omission 
was  intentional.  The  majority  of  specifications  still  call  for  "sharp"  sand, 
and  yet  the  writer  has  never  known  a  sand  to  be  rejected  simply  because  of 
its  lack  of  sharpness.  As  a  matter  of  fact,  if  two  sands  have  the  same  sized 
grains,  and  contain  an  equal  amount  of  dust,  the  one  with  rounded  grains 
is  apt  to  give  a  denser  and  stronger  mortar  than  the  sharp  grained  sand.  A 
sand  with  a  sharp  "feel"  is  preferable  to  another,  not  to  any  extent  because 
of  its  sharpness,  but  because  the  grittiness  indicates  a  silicious  sand  which  is 
apt  to  have  no  excess  of  fine  material. 

SAND  VS.  BROKEN  STONE  SCREENINGS.— Many  comparative 
tests  of  sand  and  screenings  have  been  made  with  contrary  results.  While 
frequently  crusher  screenings  produce  stronger  mortar  than  ordinary  sand, 
the  author  in  an  extensive  series  of  tests  has  found  the  reverse  to  be  true. 


This  disagreement  is  probably  due  to  the  grading  of  the  particles,  although 
in  certain  cases  the  screenings  may  add  to  the  strength  because  of  hydrauli- 
city  of  the  dust  when  mixed  with  cement. 


TESTING  SAND. 

In  the  previous  paragraphs  are  shown  the  defects  in  the  more  common 
methods  of  examining  sand. 

Tests  made  by  the  author  in  1903  proved  the  value  of  the  principles  of 
the  density  of  mortars  laid  down  by  Feret,  and  in  the  winter  of  that  year 
similar  plans  for  testing  aggregates  were  introduced  by  Mr.  William  B.  Fuller 
and  the  author  at  Jerome  Park  Reservoir,  New  York  City.  The  object  of  the 
test  is  to  determine  which  of  two  or  more  sands  will  produce  the  denser,  and 
therefore  the  stronger,  mortar  in  any  given  proportions. 

The  different  results  in  strength  which  Mr.  Feret  found  with  coarse, 
medium  and  fine  sand  respectively  have  already  been  given,  these  relative 
strengths  in  compression  being  respectively  5,200,  3,400  and  1,900  pounds, 
with  proportions  i  :2^  by  weight  in  each  case.  An  examination  of  the  tests 
shows  that  the  strongest  mortar  was  also  densest;  that  is,  the  smallest 
volume  or  yield  of  mortar  was  produced  with  a  given  weight  of  aggregate. 

The  mortar  of  medium  sand  occupied  a  volume  7^  per  cent,  in  excess  of 
the  volume  of  the  mortar  with  coarse  sand;  and  the  mortar  of  fine  sand,  a 
volume  17  per  cent,  in  excess  of  the  mortar  with  coarse  sand. 

Following  these  principles,  two  sands  may  be  compared  and  the  better 
one  selected  by  determining  which  produces  the  smallest  volume  cf  mortar 
with  the  given  proportions  by  weight.  Using  the  method  described  below, 
the  author  has  been  able  to  increase  the  strength  of  a  mortar  about  40  per 
cent,  by  merely  changing  the  sizes  of  grains  of  the  aggregate. 

The  method  of  making  the  test  is  as  follows:  If  the  proportions  of  the 
cement  to  sand  are  by  volume,  they  must  be  reduced  to  weight  proportions ; 
for  example,  if  a  sand  weighs  83  pounds  per  cubic  foot  moist,  and  the  moisture 
found  by  drying  a  small  sample  of  it  at  212°  Fahr.  is  4  per  cent.,  which  cor- 
responds to  about  3  pounds  in  the  cubic  foot,  the  weight  of  dry  sand  in  the 
cubic  foot  will  be  83—3=80.  If  the  proportions  by  volume  are  1 13,  that  is, 
one  cubic  foot  dry  cement  to  3  cubic  feet  of  moist  sand,  and  if  we  assume  the 
weight  of  the  cement  as  100  pounds  per  cubic  foot,  the  proportions  by  weight 
will  be  100  pounds  cement  to  3x80=240  pounds  sand,  which  correspond  to 
proportions  1 12.4  by  weight. 

A  convenient  measure  for  the  mortar  is  a  glass  graduate,  about  \y2  inches 
in  diameter,  graduated  to  250  cubic  centimeters.  A  convenient  weight  of 
cement  plus  sand,  for  a  test,  is  350  grams.  For  weighing,  the  author  employs 
Harvard  Trip  scales,  which  weigh  with  fair  accuracy  to  one-tenth  of  a  gram. 

42 


The  sand  is  dried  and  mixed  with  cement,  in  the  calculated  proportions,  in  a 
shallow  pan  about  10  inches  in  diameter  and  i  inch  deep.    The  mixing  is  con- 
veniently done  with  a  4-inch  pointing  trowel.     The  dry  mixed  material  is 
formed  into  a  circle,  as  in  mixing  cement  for  briquets,  and  sufficient  water 
added  to  make  a  mortar  of  plastic  consistency,  similar  to  that  used  in  laying 
brick  masonry.     After  mixing  five  minutes,  the  mortar  is  introduced  about 
20  c.c.  at  a  time  into  the  graduate,  and  to  expel  any  air  bubbles,  is  lightly 
tamped  with  a  round  stick  with  a  flat  end.     The  mortar  is  allowed  to  settle 
in  the  graduate  for  one  or  two  hours  until  the  level  becomes  constant,  when 
the  surplus  water  is  poured  off,  and  the  volume  of  the  mortar  in  cubic  centi- 
meters is  read.     For  greater  exactness,  a  correction  may  be  introduced  for 
mortar  remaining  on  pan  and  trowel.    The  other  sands,  which  are  to  be  com- 
pared with  this  one,  are  then  mixed  with  cement  in  the  same  proportions  by 
dry  weight,  and  sufficient  water  added  to  give  the  same  consistency.     The 
percentage   of  water  required  will  vary  with  the  different  aggregates,   the 
finer  sand  requiring  the  more  water.     After  testing  all  the  mortars,  the  sand 
which  produces  the  strongest  mortar  is  immediately  located  as  that  in  the 
mortar  of  lowest  volume.     By  systematic  trials,  the  best  mixture  of  two  or 
more  sands  may  also  be  found. 

In  some  cases  a  correction  must  be  introduced  for  the  specific  gravity  of 
the  sand;  for  example,  ordinary  bank  sand  has  an  average  specific  gravity 
of  2.65,  but  if  this  is  to  be  compared  with  broken  stone  screenings  having  a 
specific  gravity  of,  say,  2.80,  the  proportions  of  the  two  must  be  made  slightly 
different.  For  these  particular  specific  gravities,  proportions  1 13,  by  weight, 
with  sand,  correspond  in  absolute  volume  to  proportions  1 13.2,  by  weight, 
of  the  screenings. 

In  making  these  tests,  it  is  also  important  to  notice  the  character  of  the 
mortar  as  it  is  being  mixed.  It  should  work  smooth  under  the  trowel  and  be 
practically  free  from  air  bubbles. 

CALCULATING  RELATIVE  STRENGTHS  OF  MORTARS. 

From  the  results  of  the  tests  described,  it  is  possible  to  very  closely  esti- 
mate the  relative  strength  of  different  mortars  made  with  the  same  cement. 
A  formula  is  given  by  Mr.  Feret*  for  calculating  the  strength  from  absolute 
volumes  of  the  ingredients  of  the  mortar,  but,  wishing  to  avoid  the  calcula- 
tion of  the  absolute  volumes  and  obtain  the  result  directly  from  the  weights 
of  the  materials  and  the  volume  of  the  mortar  made  from  them,  the  writer  has 
found  it  possible  to  evolve  from  Feret's  formula  one  which  makes  use  only  of 
the  data  from  the  tests  in  the  graduates  above  described. 


Taylor  &  Thompson's  "Concrete,   Plain  and  Reinforced,"   page   139- 

43 


The  formula  is  as  follows: 

Let 

P  =   compressive  strength  of  mortar  in  pounds  per  square  inch. 

K  =  =  a  constant. 

Q  =  measured  volume  or  quantity  of  mortar  in  cubic  centimeters. 

C   -  =  weight  of  cement  used  in  grams. 

S    =  weight  of  sand  used  in  grams. 

Gc  ==  specific  gravity  of  cement. 

Gs  ==  specific  gravity  of  sand. 

Then 

C 


This  formula  may  be  readily  altered  to  apply  to  the  English  system  of 
weights  and  measures. 

The  value  of  K  varies  with  different  cements  and  different  ages  of  the 
same  mortar,  hence,  it  is  simplest  to  disregard  the  actual  strength,  and  con- 
sider the  relative  strengths  of  any  two  or  more  mortars  as  in  direct  proportion 
to  the  values  of  the  square  of  the  quantities  in  brackets. 

If  the  aggregates  to  be  compared  have  similar  specific  gravity,  as  in  the 
case  with  different  natural  sands,  the  relative  strengths  of  the  mortars  will  be 
in  proportion  to  the  values  of 

C       \2 


\GsQ-sJ 


To  illustrate  the  practical  value  of  the  formula,  aside  from  the  theory,  it 
may  be  of  interest  to  refer  to  a  recent  series  of  comparative  tests  made  in  the 
author's  laboratory.  A  mixture  of  sand  and  cement  in  proportions  70  grams 
cement  to  276  grams  sand  produced  in  the  graduate  a  volume  of  mortar  of 
178  c.  c.  After  making  a  number  of  trial  tests,  using  in  every  case  the  same 
proportions  by  weight,  a  new  mixture  of  sizes  of  the  same  aggregate  was  ob- 
tained, whose  volume  when  mixed  with  the  cement  and  water  was  165  c.  c. 
The  specific  gravity  of  the  sand,  which  in  this  instance  was  crushed  rock, 
in  both  cases  was  2.88.  Substituting  these  values  in  the  formula,  we  find  the 
ratio  of  the  two  tests  to  be  i  to  1.40,  that  is,  the  mortar  having  the  smallest 
volume  ought  to  be  1.40  times  (or  40  per  cent.)  stronger  than  the  other. 
Actual  tests  of  the  two  mortars, — afterwards  made  in  similar  proportions 
into  long  prisms, — gave  at  the  end  of  14  days  an  average  of  832  pounds  per 
square  inch  for  one  and  1,153  pounds  per  square  inch  for  the  other,  thus 
showing  an  actual  excess  of  strength  of  39  per  cent.,  which  is  substantially 
identical  with  the  estimated  increase. 

44 


TESTING  CONCRETE  AGGREGATES. 

For  concrete  in  any  given  proportions,  the  best  sizes  of  stone  and  of  sand 
may  be  determined  by  similar  methods  to  those  described  for  testing  sand 
mortars,  although  larger  quantities  of  materials  must  be  used  and  the  measure 
must  be  strong  to  withstand  the  light  ramming  which  is  necessary.  A  short 
length  of  cast  iron  pipe,  closed  at  one  end,  may  be  used  for  this. 

The  aggregates,  which  mixed  with  cement  in  the  required  proportions 
produce  the  smallest  volume  of  concrete,  are  usually  the  best,  although,  as 
already  indicated,  the  shape  of  the  particles  and  their  hardness  must  also  be 
taken  into  consideration. 

PROPORTIONING  CONCRETE. 

A  general  principle  of  practical  use  in  determining  the  relative  propor- 
tions of  two  or  more  aggregates  in  a  concrete  is  that,  the  weight  of  material 
and  the  percentage  of  cement  remaining  the  same,  the  mixture  producing  the 
smallest  volume  of  concrete  is  the  best. 


46 


CHAPTER  IV. 


PACIFIC  COAST  BORAX  REFINERY. 

The  distinction  of  being  the  designer  and  builder  of  the  first  two  rein- 
forced concrete  factory  buildings  in  the  world  undoubtedly  belongs  to  Mr. 
Ernest  L.  Ransome,  of  the  Ransome  &  Smith  Company.  Of  these  the  Pacific 
Coast  Borax  Refinery  at  Bayonne,  N.  J.,  a  few  miles  from  Jersey  City,  de- 
serves special  attention  not  only  as  one  of  the  earliest  examples  of  this  type 
of  construction,  but  for  its  notable  record  in  passing  through  a  terrific  fire 
without  structural  injury.  Moreover,  the  fact  that  it  was  not  erected  until 
1897-8  serves  to  emphasize  the  marvelous  growth  in  reinforced  concrete  con- 
struction. 

The  time  is  so  recent  and  reinforced  concrete  buildings  are  now  so  com- 
mon that  it  is  difficult  to  appreciate  the  boldness  of  the  conception  to  con- 
struct a  4-story  building,  to  sustain  actual  working  loads  of  400  pounds  per 
square  foot  besides  heavy  machinery  even  on  the  top  floor,  out  of  a  material 
until  recently  used  almost  exclusively  for  foundations,  and  considered  capable 
of  resisting  only  compressive  loads.  Of  course,  the  principle  of  steel  rein- 
forcement in  concrete  had  been  understood  for  a  number  of  years  previous  to 
1897.  In  fact>  a  house  of  reinforced  concrete  was  built  in  Port  Chester,  N.  Y., 
as  early  as  1871,  and  a  few  other  similar  structures  appeared  between  this 
date  and  1897.  But  with  the  exception  of  the  factory  at  Alameda,  Cal.,* 
also  designed  and  built  by  Mr.  Ransome,  the  Pacific  Coast  Borax  Building 
appears  to  be,  as  above  intimated,  the  first  attempt  at  concrete  factory  con- 
struction. 

While  it  is  not  claimed  that  the  design  of  this  factory  is  in  all  respects 
typical  of  the  up-to-date  concrete  factory  building  as  now  erected  by  the 
Ransome  &  Smith  Company  and  other  contractors,  many  of  its  features  and 
the  methods  employed  in  its  construction  are  well  worth  consideration. 

As  built  to-day,  double  walls  are  not  regarded  as  essential  for  factories, 
but  instead  the  wall  surface  is  usually  taken  entirely  by  windows  separated 
by  concrete  columns  which  support  the  floors  above.  In  the  floor  system, 
slabs  of  longer  span  with  correspondingly  heavier  beams  are  now  more  com- 
mon, while  expansion  joints  in  floors  are  not  usually  specified  unless  the 
building  covers  an  extremely  large  area. 

DESIGN. 
The  main  building  is  200  feet  long  by  75  feet  wide,  and  four   stories 

*  Illustrated  on  page  210. 

47 


high,  rising  70  feet  above  the  ground.  Connected  with  this  and  forming  a 
part  of  it  is  a  section  which  was  built  first  only  one  story  high,  and  then  after 
the  fire  carried  up  to  the  full  four  stories,  as  shown  in  Fig.  i.  The  area  of 
ground  covered  by  the  combined  buildings  is  50,000  square  feet. 

The  plan  of  the  first  story  is  shown  in  Fig.  2,  the  junction  between  the 
four-story  and  the  one-story  portion  being  indicated  by  the  dot  and  dash  line 
AA.  In  order  to  show  the  plan  on  a  large  scale,  the  first  floor  of  the  four- 
story  building  is  drawn  in  full  and  a  part  of  the  one-story  portion  is  omitted 
as  indicated  by  the  irregular  lines  BB. 

The  bays  in  general  are  24  ft.  8%  inches  x  12  ft.  4^  inches;  the  columns 
in  the  first  story  are  21  inches  square,  in  the  second  story  19  inches,  in  the 
third  story  17  inches,  and  in  the  fourth  story  12  inches.  They  are  computed 
by  a  maximum  compression  of  500  pounds  per  square  inch. 

The  sectional  elevation  in  Fig.  3  shows  the  columns  and  also  the  column 
footings  which  are  reinforced  in  the  bottom  with  horizontal  rods.  The  foot- 
ings were  designed  so  that  the  compression  upon  the  soil,  which  is  of  a  marshy 
character,  should  not  exceed  2,500  pounds  per  square  foot. 

Fig.  3  also  illustrates  the  construction  of  the  floor  system,  and,  taken  in 
connection  with  a  plan  of  a  portion  of  the  second  floor  in  Fig.  2,  gives  a  good 
idea  of  the  type  of  design.  Girders  connect  the  columns  which  are  12  ft.  4^ 
inches  on  centers.  Between  the  girders  and  at  right  angles  to  them,  run  the 
concrete  floor  beams  about  3  feet  apart  and  so  thin  and  deep  that  they  re- 
semble timber  joists  in  appearance.  As  these  beams  are  nearly  25  feet  long 
in  the  clear,  a  stiffening  web  crosses  them  in  the  middle  designed  to  serve 
the  same  purpose  as  bridging  in  wooden  floor  joist  construction,  that  is,  to 
assist  in  preventing  tendency  to  buckle  under  heavy  loads.  The  girders  are 
of  rather  peculiar  construction,  being  made  thicker  in  the  panels  next  to  the 
columns  so  as  to  save  expense  in  forms.  (See  Fig.  2). 

Originally,  the  columns  in  the  fourth  story  of  the  main  building  and  also 
the  roof  were  of  wood,  while  the  one-story  part  was  of  similar  construction. 
After  the  fire  the  wood  was  all  replaced  by  concrete,  as  shown  in  the  plans. 
The  roofs  were  then  built  as  reinforced  slabs  of  12  ft.  4^  inches  span  from 
centre  to  centre  of  the  beams,  the  latter  being  24  ft.  S"/s  inches  long  between 
column  centres.  Still  later  the  roof  of  the  low  part  formed  the  floor  for  the 
second  story  when  this  portion  of  the  building  was  raised  to  full  height,  as 
shown  in  the  finished  photograph,  Fig.  i. 

The  reinforcement  of  the  beams  and  girders  and  stiffeners  of  the  princi- 
pal floors  is  shown  at  the  lower  part  of  the  diagram,  Fig.  3.  The  slabs  were 
built  of  such  short  span  that  they  received  no  reinforcement,  the  depth  being 
4  inches  in  addition  to  the  i-inch  cement  finish. 

The  floors  with  the  beams  and  girders  were  laid  as  separate  panels  about 
24  feet  square,  a  vertical  contraction  joint  being  carried  down  through  the 
beams  on  a  line  with  alternate  columns;  that  is,  every  eighth  beam  was  built 
double.  As  stated  above,  it  is  not  now  customary  to  insert  contraction  joints 

48 


/%*?  of  7%D/ca/  floor  Con5frucf/0/? 


!;    <'    i'    ii     '!     ii    '!    ' 

jyLl^^j^-.-j 

t.^v^JfC;^::^;;! 

HHHHHKHHH 

i!  !•  il  >i  ii  ii  \'<  I 

fre/gfif  tfe 


-m-        m 


C/i/mney. 


-m-       m 


/*-5tor\/  -  gr.'fyvare  Co/u/nns  27" 


and  one  e 


Fig.  2. — Plan  of  First  Story  of  Pacific  Coast  Borax  Refinery.     (See  p.  48.} 

49 


50 


except  on  extraordinarily  large  surfaces,  the  contraction  being  provided  for 
instead  by  the  steel  reinforcement  in  the  beams  and  slabs. 

Details  of  the  hollow  wall  construction  are  presented  in  Fig.  4.    The  total 
thickness  of  all  the  walls  is  16  inches  for  the  entire  height  of  the  building,  the 


x    x    6    ^ 

£    £  ft  £ 

^  -«5  v  v 

8  ^  H  * 

\       c\j  CT)  ^ 


cv 


cvj 


Fig.  4.— Typical  Horizontal  Section  of  Wall.     (See  p.  5/.) 


outer  surface  being  only  2  inches  thick,  and  the  inner  surface  varying  from  4 
inches  in  the  first  story  to  i^  inches  in  the  fourth  story.  The  length  of  the 
hollow  spaces  in  the  walls  is  variable,  depending  upon  the  number  and  loca- 
tion of  the  windows.  The  webs  connecting  the  two  walls  are  3  1/16  inches 
thick  on  the  north  and  south  sides  of  the  building  and  4^  inches  thick  on  the 
east  and  west.  This  hollow  construction  has  proved  satisfactory  and  given 
a  good  roomy  building  with  no  condensation  on  the  inner  walls ;  but,  as  pre- 
viously stated,  it  is  not  now  considered  necessary  in  factory  construction  to 
incur  the  expense  of  coring  out  the  walls,  and  it  is  more  usual  to  build  them 
solid. 

The  exterior  walls  were  finished  by  picking  the  surface  with  a  sharp  tool 
which  removed  the  outside  skin  of  cement  so  as  to  show  the  stone  and  mor- 
tar between  and  resemble  pean  hammered  masonry.  A  part  of  this  work  was 
done  by  hand  and  part  with  pneumatic  hammers.  Although  a  pneumatic 
hammer  averaged  about  400  square  feet  in  ten  hours,  while  by  hand  100  to 
150  square  feet  was  a  fair  day's  work  for  a  man,  the  actual  cost  with  the  power 
tool  was  but  slightly  less  than  by  hand  because  of  the  higher  grade  of  men 
required,  the  extra  men  for  shifting  air  pipes,  etc.,  and  the  wear  and  tear  on 
the  tools. 


t 2£- 

Fig.  5.— Molding  of  Wall  Joints.*     (See  p.  52.} 


The  surface  was  also  divided  into  blocks  by  wood  moldings  nailed  to  the 
inside  of  the  form.  A  section  of  the  molding  is  shown  in  Fig.  5. 

The  stairs  are  also  of  reinforced  concrete,  typical  details  being  given  in 
Fig.  6. 


Fig.   6. — Sketches   of    Stair   Construction.     (See  p.  5^. 


In  Fig.  7  is  shown  the  150  foot  concrete  chimney  which  is  located  in  the 
middle  of  the  building.  (See  Fig.  2).  It  was  built  with  two  independent 
shells  of  concrete. 


PROPORTIONS  OF  THE  CONCRETE. 

The  proportions  of  cement  to  aggregate  in  the  concrete  varied  in  differ- 
ent parts  of  the  work.  For  the  aggregate,  broken  basaltic  rock  brought  down 
from  the.  Palisades  of  the  Hudson  was  chiefly  used.  The  size  was  limited  to 

*    Reproduced  by  permission   from   Taylor   &  Thompson's   "Concrete,   Plain   and   Reinforced." 

52 


-^ 


!p22Z_ 


-ryr- 


r 


Concrete 


Fig.  7. — Plan  and  Elevation  of  Chimney.     (See p.  52.) 

53 


particles  passing  a  2-inch  ring,  while  for  much  of  the  work  that  which  passed 
a  i -inch  ring  was  employed.  The  dust  was  left  in  the  rock  and  provided  so 
much  fine  material  that  only  a  small  quantity  of  sand,  averaging  not  more 
than  10  per  cent.,  was  needed. 

The  proportions  of  the  footings  were  i  part  Atlas  Portland  cement  to 
10  parts  of  this  aggregate.  The  columns  were  of  1 15  mixture,  and  the  walls, 
floors  and  stairs  of  1:6^. 

For  imbedding  the  rods  in  the  bottom  of  the  floor  beams  a  i  :6  mix  was 
employed,  using  very  fine  stone  for  the  concrete. 

Concrete  of  i  :6^2  proportions  made  into  3-inch  cubes  gave  a  compressive 
strength  of  900  pounds  per  square  inch  at  the  age  of  7  days. 

CONSTRUCTION. 

Construction  was  begun  late  in  the  fall  of  1897  and  completed  in  October 
1898.  The  usual  time  per  story  was  40  to  50  days,  whereas  now  such  a  build- 
ing would  be  put  up  by  the  same  builders  at  the  rate  of  a  story  in  one  or  two 
weeks.  > 

The  materials  for  the  concrete  included  10,000  barrels  of  cement  and 
nearly  as  many  cubic  yards  broken  stone,  the  stone  being  brought  in  scows 
down  the  Hudson  River  and  piled  near  the  shed,  in  which  1,000  bags  of 
cement  were  stored. 


Fig.  8.— Type  of  Wall  Molds.     (See  p.  55.) 

The  construction  plant  was  of  quite  elaborate  design.       The     cement 
having  been  wheeled  from  the  shed  and  the  stone  measured  in  barrows,  both 

54 


materials  were  dumped  into  a  hopper  which  discharged  into  a  car.  This  car 
was  hauled  by  cable  through  a  subway  and  then  up  an  incline  to  about  30 
feet  above  the  hopper  and  about  400  feet  distant,  where  it  was  automatically 
tipped  into  a  chute  leading  to  the  mixer.  The  mixer,  of  substantially  the 
same  type  as  the  Ransome  machines  now  in  general  use,  discharged  into  a 
trough  containing  a  screw  conveyor  which  delivered  the  wet  concrete  to  a 
vertical  bucket  elevator  and  this  hoisted  the  material  to  the  story  where  it 
was  required,  and  dumped  it  upon  a  platform  which  held  about  one  cubic 
yard. 

A  steam  engine  operated  the  car,  mixer  and  elevator,  and  also  ran  a 
twisting  machine,  bolt  cutter  and  two  or  three  other  tools.  The  column 
forms  were  built  in  the  usual  way  with  vertical  boards  paneled  together,  and 
held  with  clamps  surrounding  them.  The  wall  forms  were  %  inch  dressed 
boards,  designed  in  general  like  Fig.  8. 

These  forms,  patented  by  Mr.  Ransome  in  1885,  are  still  extensively 
used  in  wall  construction.  The  special  feature  is  the  vertical  standard  made 
of  two  i  by  6  inch  boards  on  edge  with  a  slot  between,  through  which  passes 
the  bolts.  By  loosening  the  nut,  the  plank  behind  the  standards  may  be 
loosened  and  the  standards  raised.  The  walls  were  built  in  sections  4  feet 
high  with  central  cores  to  form  the  hollow  walls. 

White  pine  was  used  for  forms,  and  the  salvage  on  the  lumber  probably 
did  not  amount  to  more  than  10  per  cent.,  although  by  present  methods  the 
builders  usually  figure  about  30  per  cent. 

The  total  cost  of  the  building  was  in  the  neighborhood  of  $100,000. 

THE  FIRE. 

Some  four  years  after  completion,  in  the  spring  of  1902,  the  Refinery  was 
subjected  to  one  of  the  most  severe  fires  to  which  a  manufacturing  building 
is  liable.  Although  the  building  itself  is  of  concrete,  it  contained  a  large 
amount  of  wood  in  the  form  of  partitions,  window  frames  and  bins,  in  addi- 
tion to  the  wooden  roof,  and  at  the  time  of  the  fire  one  room  happened  to  be 
completely  filled  with  empty  wooden  casks  which  provided  yet  more  fuel  for 
the  flames.  Some  of  the  material  used  in  the  manufacturing  process  was  also 
extremely  inflammable. 

To  illustrate  the  heat  of  the  fire,  an  insurance  man  called  attention  to  the 
fact  that  the  plank  roof  was  entirely  gone,  with  no  charred  wood  remaining, 
the  brass  in  the  dynamos  was  melted,  and  at  least  in  one  case  a  piece  of  cast 
iron  was  fused  into  a  misshapen  mass.  A  photograph  of  the  melted  cast  iron 
is  shown  in  Fig.  9. 

This  fusing  of  the  iron  is  especially  remarkable  since  cast  iron  melts  at 
the  high  temperature  of  about  2,200°  Fahr.  The  piece  appears  to  be  a  portion 
of  a  pulley  which  was  probably  located  near  an  opening  in  the  floor  through 
which  there  was  a  tremendous  draft  of  flame. 

55 


Fig.  9. — Photograph  of  Cast  Iron  Melted  by  the  Fire.      (See  p.  55.) 

The  chief  structural  damage  to  the  building  at  the  time  of  the  fire  was 
caused  by  the  fall  of  an  iron  tank  which  was  located  on  the  wooden  roof  and 
supported  by  timbers  from  the  fourth  floor.  This  weight  coming  suddenly 
upon  the  floor  broke  the  slab  and  tow  or  three  of  the  floor  beams,  but  did  not 
pass  through  to  the  floor  below,  being  caught  by  the  damaged  floor. 

In  several  places  throughout  the  building  the  concrete  had  been  split  off 
by  the  fire  to  a  depth  of  y±  to  one  inch,  and  on  one  of  the  exterior  walls  a  few 
cracks  showed  over  a  doorway.  The  total  cost  of  repairs,  including  the  por- 
tion of  the  floor  broken  by  the  tank,  was  in  the  neighborhood  of  $1,000.  The 
broken  beams  were  repaired  by  inserting  new  concrete  in  the  central  portion 
and  supporting  it  by  bolts  run  down  through  the  ends  of  the  beams  which 
still  remained  in  place. 

As  a  result  of  the  fire  the  structure  was  completely  gutted,  nothing  re- 
maining but  the  reinforced  concrete  and  a  mass  of  charred  wood,  with  the 
machinery,  shafting,  dynamos,  etc.,  melted  or  twisted  out  of  shape.  A  photo- 
graph taken  directly  after  the  disaster  before  any  repairs  were  made  is  given 
in  Fig.  10.  This  photograph  also  presents  a  very  good  view  of  the  Refinery 
itself  with  the  main  building  and  the  one-story  addition. 

In  contrast  with  the  durability  of  the  reinforced  concrete  under  the  action 

56 


c> 

1— I 

bb 


57 


Fig.  11.— Effect  of  Fire  Upon  Steel  Tank  House.     (See  p. 


of  the  fire  is  a  steel  tank  house  adjoining  the  building.  This  was  built  with 
steel  columns  and  roof  girders,  and  the  effect  of  the  heat  upon  the  steel  struc- 
ture is  graphically  shown  in  Fig.  n. 

A  photograph  of  the  Refinery,  taken  in  1907  and  shown  as  Fig.  i  on  page 
46,  presents  one  view  of  the  buildings,  and  in  Fig.  12  is  another  1907  view, 
showing  in  the  foreground  the  new  part  also  built  by  Ransome  &  Smith  and 
the  older  structure  in  the  background. 


59 


Fig.   14.— The  Ketterlinus  Building.     (See  p.  6/.) 
60 


CHAPTER  V. 


KETTERLINUS  BUILDING. 

The  plant  of  the  Ketterlinus  Lithographic  Manufacturing  Company  is 
located  in  Philadelphia  at  the  northwest  corner  of  Fourth  and  Arch  streets, 
and  the  reinforced  concrete  portion  of  the  structure  built  in  1906  represents 
a  type  of  building  adapted  to  city  manufacturing  establishments  limited  to  a 
comparatively  small  ground  area.  The  building  illustrated  on  the  opposite 
page  as  Fig.  14  is  eight  stories  high  besides  the  basement,  and  its  dimensions 
are  80  by  67  feet.  The  architects  and  engineers  were  Ballinger  &  Perrot,  of 
Philadelphia,  and  they  also  supervised  the  erection,  which  was  done  by  day 
labor  with  no  general  contractor. 

This  new  building  adjoins  and  forms  a  part  of  the  old  plant  of  the  Ketter- 
linus Company,  which  is  of  steel  frame  construction,  fireproofed  with  terra 
cotta. 

In  both  buildings  heavy  machinery  is  now  running,  and  many  large  print- 
ing presses  are  at  work  on  the  third,  fourth  and  fifth  floors.  Because  of  the 
proximity  of  the  old  and  new  types  of  construction  the  advantages  of  the  re- 
inforced concrete  from  the  point  of  view  of  the  manufacturer  are  particularly 
evident.  In  the  building  of  steel  and  terra  cotta  construction  the  vibration 
from  the  machinery  is  noticeable  as  soon  as  one  enters,  while,  on  the  other 
hand,  in  the  new  structure  the  concrete  because  of  its  greater  mass  and  inertia, 
absorbs  the  vibrations,  and  it  is  difficult  to  appreciate  the  speed  and  power 
of  the  machines.  As  a  result,  too,  of  this  reduction  in  the  vibration  the  noise 
of  the  machinery  is  effectually  deadened. 

The  building  is  designed  for  a  working  load  of  400  pounds  per  square 
foot.  The  concrete  for  practically  the  whole  of  the  work  was  proportioned 
i  :2l/2  15,  equivalent  by  actual  measurement  to  one  barrel  (4  bags)  Atlas  Port- 
land cement  to  gl/2  cubic  feet  of  sand  to  19  cubic  feet  broken  stone,  the  basis 
of  proportioning  is  in  a  barrel  of  3.8  cubic  feet.  The  sand  was  well  graded 
coarse  material,  frequently  termed  in  the  region  of  Philadelphia  "Jersey  grav- 
el" ;  the  stone  was  trap  rock  broken  to  a  size  at  which  all  the  particles  would 
pass  a  one-inch  ring  excepting  the  stone  in  the  concrete  immediately  sur- 
rounding the  steel,  which  was  of  a  size  to  pass  through  a  half-inch  ring. 

To  harmonize  with  the  old  adjoining  building  of  which  it  forms  a  part, 
the  exterior  walls  are  faced  with  brick  with  terra  cotta  trimmings. 

DESIGN. 

Several  features  in  the  design  of  the  Ketterlinus  building  are  of  unusual 

61 


interest.  The  columns  below  the  fifth  floor,  instead  of  the  usual  solid  con- 
crete construction  with  four  or  more  round  rods  for  reinforcement,  are  es- 
sentially steel  columns  surrounded  by  concrete.  The  beams  and  girders  are 
reinforced  with  the  unit  frame  system  in  which  the  steel  is  all  put  together 
in  the  shop  and  brought  to  the  job  ready  to  place  in  the  form.  The  sawtooth 
roof  is  also  a  novel  feature  for  reinforced  concrete. 

The  columns  are  spaced  13  feet  6  inches  apart  in  one  direction  and  19 
feet  2  inches  in  the  other.  The  girders  follow  the  shorter  span,  and  the  bays 
are  divided  into  three  panels  by  the  cross  beams,  as  shown  in  Fig.  15.  The 
vertical  section,  Fig.  16,  also  illustrates  the  arrangement  of  the  columns  and 
beams,  the  window  lintels  and  the  sections  of  brick  wall  below  the  windows. 


Fig.  15. — Typical  Floor  and  Roof  Plans  of  the  Ketterlinus  Building.     (See  p.  62.} 

62 


0v//d//?f 


Fig.   16. — Cross-Section  of  Ketterlinus  Building. 

63 


COLUMNS. 

One  of  the  problems  in  concrete  building  construction  where  the  loads 
are  heavy  or  the  building  is  several  stories  high  is  to  build  the  columns  small 
enough  to  satisfy  the  requirements  of  the  occupants  and  owners  without  over- 
loading the  concrete.  Its  solution  is  especially  difficult  in  a  city  building  where 
the  land  area  is  so  valuable  that  every  square  inch  of  floor  space  is  at  a  pre- 


l!i  !  ii!  !  H      If      " 

j^r.^eKrAy.-H! 

Jj^T/t'-t^t 


•ffeo HT  VIEW  •'"'•  Gffii_i_A,ac:-  ?>- CoL-un  N 


' DETAIL- oir*UNinr«  GIRBER*  FRAME  *  CONSTRUCTION 

STAR     SHAPED)-   STEEL    TOJEINFOTRCEMENT    IN  COLUMN 
BALLINOEE   ^    PER  ROT 


Fig.  17.—  Details  of  Columns  and  Girders. 


/>.  65.) 


mium,  and  where  there  must  be  more  stories  than  are  economical  under  other 
conditions.  Moreover,  the  building  laws  of  many  cities  require  more  conser- 
vative loading  than  might  be  warranted  if  it  were  certain  that  the  conditions 
of  construction  were  in  all  cases  the  best. 

In  a  number  of  recent  instances  the  difficulty  has  been  met  by  the  use  of 
composite  columns,  a  combination  of  concrete  and  structural  steel,  and  this 
is  the  plan  followed  by  the  designers  of  the  Ketterlinus  building.  Full  details 
of  the  column  construction  are  presented  in  Fig.  17. 

The  interior  columns  in  the  building  up  to  the  fifth  floor  are  23  inches  in 
diameter.  In  the  basement  and  the  four  lower  stories,  the  core  of  the  column 
is  formed  of  steel  plates  and  angle  irons  riveted  together  in  the  form  of  a 
cross.  Around  this  cross  y%  inch  wire  ties  were  placed  every  12  inches  and 
looped  around  four  vertical  round  rods  which  increased  the  reinforcement. 
In  the  basement,  for  example,  the  centre  steel  is  made  up  of  a  plate  18  inches 
wide  and  ?x,  inch  thick  with  two  plates  of  similar  thickness  but  8  inches  wide 
at  right  angles  to  it,  and  four  angle  irons  6  by  6  by  -;  H  mch  all  riveted  together. 
The  four  round  rods,  which  complete  the  so-called  "Star"  reinforcement  are 
il/$  inch  diameter. 

The  columns  in  the  three  stories  nearest  the  top  are  designed  to  carry  the 
full  dead  and  live  loads  of  floors  and  roof.  In  each  lower  story  the  columns 
are  designed  to  carry  the  full  dead  load  and  a  smaller  proportion  of  the  full 
live  load  than  can  be  carried  by  the  floor  construction,  this  live  load  factor 
being  reduced  proportionately  to  the  number  of  floors  carried ;  for  example, 
the  basement  columns  were  calculated  on  a  basis  of  carrying  on  the  steel  cores 
alone  three-fourths  the  live  load  plus  the  full  dead  load  with  a  factor  of  safety 
of  4. 

The  steel  is  designed  to  bear  the  computed  load  without  exceeding  a 
maximum  compression  of  16,000  pounds  per  square  inch.  The  compressive 
strength  of  the  concrete  in  these  columns  is  not  considered,  though  almost 
sufficient  to  carry  the  dead  load. 

The  weight  of  the  girders  is  borne  in  part  by  brackets  of  steel  riveted  to 
the  angle  irons  and  partly  by  the  concrete  knees  or  enlargements  of  the 
column  which  run  out  obliquely  from  the  columns  and  which  are  reinforced 
on  each  side  by  two  ^-inch  rods. 

Above  the  fourth  story  the  columns  are  of  the  same  diameter  but  with 
the  more  ordinary  reinforcement  of  four  round  rods. 

COLUMN  FOOTINGS. 

To  transmit  the  compressive  load  from  the  steel  in  the  columns  to  the  soil, 
a  special  design  of  footing  was  prepared.  A  large  base  was  necessary  to  pre- 
vent too  great  loading  of  the  soil  beneath  the  building,  and  in  order  that  the 
pressure  from  the  column  might  not  break  or  crush  the  concrete  over  this 
large  area  a  grillage  of  steel  I-beams  was  placed  under  each  column  (See  Fig. 

65 


17),  and  the  concrete  below  these  I-beams  further  strengthened  against  break- 
age and  shear  by  i-inch  horizontal  round  rods  placed  6  inches  apart,  and  l/& 
by  i -inch  stirrups. 

FLOOR  SYSTEM. 

Each  girder  was  designed  as  an  independent  beam  supported  at  the  ends 
by  the  enlargement  of  the  columns  and  the  steel  brackets.  The  area  of  the 
reinforcing  steel  was  calculated  in  the  usual  way,  but  instead  of  placing  each 
rod  separately  in  the  form,  girder  frames  were  made  from  quadruple  or  twin 
webbed  bars,  which  were  cut,  bent  to  shape  and  stirrups  fastened  thereto  in 
the  shop.  The  girder  frame  reinforcement  was  brought  to  the  building  in  the 
form  of  a  truss,  and  the  work  of  placing  consisted  simply  of  setting  this  truss 
in  the  form  upon  cast  steel  sockets,  each  having  a  )4-inch  threaded  stud  pro- 
jecting upward  through  the  frame.  A  nut  screwed  down  on  this  stud  over 
the  frame  holds  it  rigidly  in  position.  Every  rod  and  every  member  could  not 
help  but  be  in  exactly  the  right  location  in  the  beam.  This  girder  frame  and 
socket  were  the  invention  of  Emile  G.  Perrot,  one  of  the  firm  of  architects 
who  designed  the  building,  the  object  being  to  insure  the  exact  amount  and 
arrangement  of  tension  and  shear  members  in  the  exact  location  as  designed, 
and  to  afford  opportunity  for  inspection  of  the  steel  in  position  before  the 
pouring  of  the  concrete. 

In  the  various  plans  the  letter  "Q"  is  entered  as  a  part  of  the  description 
of  the  reinforcement.  This  stands  for  the  word  "Quadruple"  and  indicates  a 
group  of  four  rods  held  at  intervals  by  special  sockets. 

The  rods  are  rolled  in  sets  of  four  connected  by  a  web,  and  this  web  is 
sheared  and  bent  down  in  2-inch  lengths  at  intervals  of  3  inches  to  give 
greater  grip  in  the  concrete.  These  2-inch  lengths  are  bent  back  over  stir- 
rups, where  they  occur,  to  clinch  them  in  position  on  the  frame.  The  outside 
bars  are  also  cut  loose  at  each  end  and  bent  upwards  to  reinforce  the  top  of 
the  beam  near  the  supports.  The  sockets  (Fig.  17)  are  shaped  so  that  they 
support  the  rods  i1/*  inches  above  the  bottom  of  the  beam  or  girder,  and  are 
held  in  place  by  a  ^-inch  bolt  passing  up  through  the  bottom  of  the  wood 
mold.  These  threaded  sockets  afterwards  are  used  for  securing  shafting, 
hangers  or  other  fixtures. 

In  the  various  dimensions  of  beams  on  the  plan  the  width  and  depth  is 
given  first,  followed  by  "i  Q"  or  "2  Q"  (the  latter  meaning  8  rods),  then  the 
diameter  of  rod,  and  finally  the  thickness  of  the  web  forming  a  part  of  the  rods. 
Thus  io"xi8"-2Q%"x;^"  means  that  the  beam  is  10  inches  wide  by  18  inches 
deep,  reinforced  with  two  groups  of  four  rods  7/s  inch  diameter,  connected 
longitudinally  by  webs  %  inch  thick.  The  depth  of  the  beams  and  girders  is 
given  from  the  under  side  of  the  slab  instead  of  from  the  top  of  the  slab,  the 
more  usual  form.  The  area  of  cross-section  of  each  of  such  "Q"  bars  is 
about  3  square  inches. 

The  slabs  are  of  usual  construction,  being  4  inches  thick  and  reinforced 
for  the  net  span  of  3  feet  10  inches  with  3-inch  No.  10  expanded  metal,  this 

66 


mesh  having  been  substituted  instead  of  ^-inch  rods  spaced  6  inches  apart 
and  occasional  %-inch  rods  running  in  the  other  direction,  as  originally  shown 
on  the  drawings,  at  an  increase  of  about  one  per  cent,  of  the  cost  of  the  build- 
ing. 

The  wearing  surface  is  a  i^-inch  maple  wood  floor  on  2  by  4  inch  sleep- 
ers 1 6  inches  apart.  The  sleepers  are  placed  on  the  concrete  slab  and  cinder 
concrete  in  proportions  1 13  17  rilled  in  between  them. 

STAIRS. 
The  stairs  are  carried  up  in  brick  towers,  as  required  at  date  of  construc- 


£&//7  forced  Co/?cr<?/e 


Fig.  18.  —  Stairs  in  Ketterlinus  Building.     (See  p.  67.) 


tion  by  the  Philadelphia  building  laws.     The  details  of  the  design  and  rein- 
forcement are  illustrated  in  Fig.  18. 

The  treads  are  formed  by  i  inch  thickness  of  i  to  i  mortar  or  grano- 
lithic finish,  and  the  reinforcement  consists  of  ^-inch  rods  placed  6  inches 
apart. 

WALLS. 

The  walls  are  essentially  reinforced  concrete  columns,  veneered  on  the 
outside  with  4  inches  of  brickwork  and  separating  the  windows.  The  window 
lintels  are  of  concrete  faced  with  terra  cotta  to  match  the  red  sandstone  of  the, 
older  building  adjoining  and  anchored  to  the  concrete.  The  lintels  form  re- 
inforced concrete  beams  and  support  a  brick  wall  13  inches  thick,  which  is  run 
up  to  the  bottom  of  the  terra  cotta  window  sills. 

The  method  of  connecting  the  brick  with  the  concrete  of  the  columns 
is  shown  in  Fig.  19,  copper  wall  ties  1/16  by  >}4  by  7  inches  being  set  in  the 
concrete  at  intervals,  and,  after  the  removal  of  the  forms,  bent  out  and  laid 
into  the  joint  of  the  face  brick,  which  is  separated  from  the  concrete  by  a 
mortar  joint  for  purposes  of  alignment. 


\fr\- :>*rc:#:#: 
:&:&:•.•:•*:&.# 


i^F^i 

.-••••v-SX-A:^ 
??:  8  $  && 


Fig.   19.— Brick  Wall  Ties.     (5Vc  />. 

ROOF. 

The  general  design  of  the  saw-toothed  roof  appears  on  the  full  cross- 
section,  Fig.  1 6  (p.  63).  In  Fig.  20  the  details  are  illustrated.  Inclined  gird- 
ers extend  across  the  building,  and  above  these  project  the  saw  teeth,  which 
rest  upon  concrete  beams  running  into  the  girders.  Saw-tooth  construction 
in  reinforced  concrete  is,  of  course,  expensive,  because  of  the  irregularities  of 
the  forms,  but  with  the  aid  of  the  unit  reinforcing  system,  which  accurately 
locates  the  steel,  the  design  is  satisfactorily  worked  out. 

As  in  the  other  plans,  the  letter  Q  indicates  a  quadruple  bar  whose  web 
thickness  is  designated  by  the  final  fraction  in  the  dimensions.  In  the  roof, 
instead  of  the  four  bars  being  on  one  plane  and  rolled  all  together  with  a 
single  web,  they  are  arranged  in  pairs  with  a  web  connecting  the  two  bars 
of  each  pair. 

68 


I[ 

\ 

fisar 

| 

| 

Jj 

_-l~ 

\ 

Fig.  20. — Cross-Section  Detail  of  Saw-Tooth  Roof.     (Sec  p.  68.} 

CONSTRUCTION. 

The  concrete  was  mixed  in  the  basement  by  a  Smith  machine,  dumped 
from  the  mixer  into  wheelbarrows  and  raised  on  a  platform  elevator  located 
in  the  stair  tower  to  the  floor  in  process  of  construction,  when  it  was  wheeled 
in  the  same  barrows  and  dumped  directly  into  the  columns  or  floor. 

A  boom  derrick  was  employed  to  handle  the  steel  columns,  lumber  and 
brick.  This  derrick  was  also  used  for  demolishing  and  excavating  before  the 
concrete  was  started. 

A  photograph  of  one  of  the  floors  ready  for  the  concrete  is  shown  in  Fig. 
21.  The  wood  forms  for  the  beams,  girders  and  slabs  are  in  place,  and  the 
steel  of  the  columns  is  set  and  temporarily  braced  with  plank.  In  different 
places  on  the  floor  the  unit  girder  frames  are  seen,  some  of  them  in  place 
in  the  mold  and  some  lying  on  the  floor  ready  to  be  carried  and  lowered  to 
position. 

Fig.  22  shows  the  exterior  of  the  building  in  a  later  stage  of  the  construc- 
tion. The  column  forms  have  not  yet  been  removed  from  some  of  the  columns, 
and  many  of  the  braces  are  still  in  place.  The  framework  of  the  platform 
elevator  projects  above  the  structure  at  the  left  of  the  photograph,  while  the 
boom  derrick  is  seen  to  be  located  on  the  roof  of  the  old  part  of  the  building. 

The  progress  per  story  varied  from  eleven  days  to  three  weeks.  The 
forms  were  left  in  place  two  weeks  or  more  and  were  used  three  times,  the 
approximate  salvage  on  the  lumber  for  the  next  job  being  25  per  cent. 

The  interior  of  the  building  is  photographed  in  Fig.  23  (p.  72),  and  shows 
one  of  the  2o-ton  lithographic  presses. 

69 


Fig.  22. — Exterior  of  the  Ketterlinus  Building  During  Construction.    (See  p. 

71 


.5 
O 

j: 

CO 

bB 

c 


bJD 


COST. 

The  concrete  portion  of  the  building  cost  $27,000.  This  sum  included  the 
form  work  and  steel  reinforcement,  except  the  column  cores  and  grillage 
beams,  which  cost  $5,500  additional.  The  total  cost  of  the  structure,  includ- 
ing the  inside  finish,  amounted  to  nearly  $90,000. 

The  unit  girder  construction  is  somewhat  more  expensive  than  the  ordi- 
nary system  of  bending  and  placing  separate  rods,  but  the  result  is  a  sure 
location  for  every  member  with  no  danger  of  a  rod  being  left  out  or  placed  so 
high  as  to  lose  a  large  part  of  its  efficiency.  In  this  particular  building  the 
cost  of  the  unit  girder  reinforcement  was  4  cents  per  pound  after  bending 
ready  to  place. 

INSURANCE. 

It  is  of  interest  to  observe  that  the  building  is  insured  by  the  Associated 
Factory  Mutual  Insurance  Companies,  and  at  the  time  of  completion  was  the 
only  building  in  the  congested  portion  of  Philadelphia  which  was  insured 
by  them. 

As  a  protection  against  fires  in  neighboring  structures,  the  building  is 
fitted  with  wire  glass  windows  with  metal  frames,  except  in  the  first  story, 
which  has  plate  glass  windows  with  metal  frames.  Openings  in  the  division 
wall  between  the  old  and  new  parts  of  the  plant  are  closed  with  automatic 
fire  doors  on  both  sides  of  the  fire  wall.  Furthermore,  the  building  is  equip- 
ped with  automatic  sprinklers  supplied  by  a  tank  located  20  feet  above  the 
roof.  The  sprinklers  are  also  connected  with  a  75o-gallon  Underwriters'  fire 
pump  supplied  by  two  independent  6-inch  connections  from  the  distribution 
system  of  the  city  waterworks,  and  the  tank  above  the  roof  and  standpipes 
in  the  building  are  also  supplied  from  this  pump.  In  addition  to  this  private 
fire  system,  a  standpipe  extending  to  a  nozzle  monitor  on  the  roof  is  also  pro- 
vided, which  is  connected  with  the  Underwriters'  pump  and  also  with  the 
high-pressure  city  mains  by  means  of  hose. 


73 


Fig.  24. — Lynn  Storage  Warehouse.     (See  p.  75.) 
74 


CHAPTER  VI. 


LYNN  STORAGE  WAREHOUSE. 

The  Lynn  Storage  Warehouse,  at  Lynn,  Mass.,  is  built  for  the  storage  of 
general  merchandise  and  furniture,  reinforced  concrete  having  been  selected 
,as  the  most  economical  fireproof  construction.  To  provide  for  the  variable 
character  of  its  contents,  the  several  floors  are  designed  to  sustain  different 
loading;  the  three  lower  floors  are  each  planned  for  the  rather  heavy  loading 
of  250  pounds  per  square  foot,  while  on  the  fourth  floor  200  pounds  per  square 
loot  of  loading  is  to  be  allowed,  and  on  the  fifth  and  sixtty  floors  150  pounds. 
A  possible  weight  of  50  pounds  per  square  foot  is  provided  for  in  the  roof 
design. 

The  building  shown  in  Fig.  24  is  six  stories  high  besides  the  basement, 
being  50  feet  wide  by  165  feet  long.  Although  not  strictly  speakmg  a  fac- 
tory building,  the  design  is  typical  of  first-class  factory  construction. 

An  interesting  feature  of  the  layout  is  the  omission  of  the  first  floor  in 
the  corner  of  the  building  near  the  large  elevator,  in  order  to  provide  sufficient 
head  room  for  teams  to  drive  in  and  deposit  their  load  upon  the  ek'.vator,  or 
else,  if  preferred,  to  drive  directly  on  to  the  elevator,  which  is  n  x~  12  feet 
in  area,  so  that  the  wagon  and  horses  can  be  elevated  to  the  floor  wl»ere  the 
goods  are  to  be  placed  and  hauled  to  the  proper  point. 

The  designers  of  the  reinforced  concrete  and  also  the  builders  are  the 
Eastern  Expanded  Metal  Company,  of  Boston,  Mr.  J.  R.  Worcester  being 
consulting  engineer.  The  architect  is  Mr.  D.  A.  Sanborn,  of  Lynn. 

A  full  cross-section  of  the  warehouse,  showing  the  dimensions  of  the 
members  and  the  general  scheme  of  design,  as  shown  in  Fig.  25..  Fig.  26 
gives  typical  floor  plan  and  also  detail  plan  and  sections  of  the  stairs^ 


FLOOR  CONSTRUCTION. 

i 

Round  rods  are  used  for  reinforcement  of  the  beams,  girders  and  -columns, 
while  expanded  metal*  forms  the  slab  reinforcement. 

The  designs  were  carefully  worked  up  by  the  Eastern  Exp,ande  d  Metal 
Company  and  checked  by  Mr.  Worcester  as  consulting  engine  er.  1  'he  sec- 
tional view  (Fig.  25)  clearly  illustrates  the  general  scheme  of  reinforcing. 
Complete  details  of  a  typical  girder,  beam  and  slab,  designed  to  safely  sustain 
150  pounds  per  square  foot  of  the  floor  load  in  addition  to  th.e  weight'  of  the 
concrete,  are  drawn  in  Fig.  27  (page  79).  The  slab,  as  indie  itetf,  is  §  fceet  in 

*   See  jUlustxajJiwi ,  Fig.    108,   page   182.  4  li 

75  - 


Fig.  25.— Cross-Section  Through  Lynn  Storage  Warehouse.     (See  p.  75-) 


erf/ca/£od5  4  <-  ZA' 
Horizontal 


Fig.  26.— Typical  Plan  and  Typical  Stair  Details  of  Lynn  Storage  Warehouse. 

(See  p.  75-} 


77 


width  from  center  to  center  of  beam  or  5  feet  3  inches  in  net  span.  The  beams 
are  17  feet  9  inches  from  center  to  center  of  girders  or  17  feet  net  span.  The 
girders  are  12  feet  between  centers  of  columns  or  iol/2  feet  net  span. 

The  expanded  metal  reinforcement  is  placed  near  the  bottom  of  the  slab 
in  the  center  of  its  span,  and  rises  up  to  the  top  of  the  slab  over  the  beams 
to  provide  for  negative  bending  moment.  The  metal  used  is  3-inch  mesh, 
No.  10  gage,  this  being  equal  to  a  cross-section  of  0.175  square  inches  per  foot 
of  width  of  slab,  or  0.5  per  cent,  of  the  cross-section  of  the  slab  area  above 
the  steel. 

In  the  beams  three  i-inch  rods  are  imbedded,  one  of  them  bent  up  at  the 
quarter  points  and  running  horizontally  over  the  supports  so  as  to  lap  by  the 
rod  from  the  next  bay,  thus  giving  two-thirds  as  much  reinforcement  over  the 
supports  as  in  the  center  of  the  beam.  The  stirrups  are  flat  steel  ^  inch  by 
i  inch.  Notice  from  Fig.  25  that  in  the  three  lower  stories,  where  the  loading 
is  heavier,  there  are  five  stirrups  in  each  end  of  the  beam  instead  of  two.  The 
beams  in  these  lower  stories  are  made  the  same  size,  9  inches  by  20  inches,  in 
order  to  use  the  same  forms  throughout  the  building,  but  the  reinforcement  is 
heavier. 

The  typical  girders  in  Fig.  27  have  five  %-inch  rods  at  the  center,  two  of 
them  bent  up  and  running  on  an  incline  from  the  center  of  the  span.  The  in- 
cline starts  at  the  center  of  the  girder  instead  of  one-quarter  way  from  each 
end,  because  the  girder  having  its  greatest  load  at  the  center,  the  shear  is 
nearly  uniform  throughout  the  entire  span. 

Instead  of  the  more  usual  practice  of  forming  the  wall  girders  as  a  part 
of  the  wall,  they  are  built  independently  of  the  wall  slab,  as  indicated  in 
Fig.  25. 

FLOOR  SPECIFICATIONS. 

There  are  several  points  of  particular  interest  in  the  floor  specifications, 
and  without  copying  them  entire  a  brief  outline  is  worth  noting,  as  the  data 
are  quite  full  and  the  requirements  conservative. 

The  slabs  are  calculated  with  a  bending  moment  i/io  WL  in  cases  where 
three  or  more  slabs  are  continuous,  while  for  the  wall  slabs  y$  WL  is  em- 
ployed. The  working  strength  of  the  concrete  in  compression  is  limited  in 
the  slabs  to  500  pounds  per  square  inch  if  computed  by  the  parabolic  method 
of  stress,  which  is  equal  to  about  600  pounds  by  the  more  usual  straight  line 
method.  The  slab  steel  is  limited  to  16,000  pounds  per  square  inch  in  tension, 
the  ratio  of  the  modulus  of  steel  to  that  of  concrete  being  taken  as  15.  At 
right  angles  to  the  length  of  the  span  i/io  square  inch  of  steel  is  required  per 
foot  of  length  of  slab,  which  with  the  4-inch  slab  is  equivalent  to  about  0.25 
per  cent.  A  thickness  of  y|  inch  of  concrete  is  required  below  the  metal  in 
the  slabs. 

The  bending  moment  in  the  beams  and  girders  is  considered  as  y8  WL. 
The  beams  are  considered  as  T-beams  in  computing  their  strength,  and  it  is 
specified  that  the  width  of  the  flange  shall  not  exceed  one-third  the  span,  and 

78 


«      et 


79 


that  the  average  compression  in  the  flange  shall  not  exceed  two-thirds  of  the 
extreme  fiber  stress. 

The  vertical  shear  in  the  concrete  in  beams  which  are  not  reinforced  for 
shear  is  limited  to  one-tenth  the  extreme  compressive  working  stress  in  the 
concrete,  and  it  is  assumed  that  this  vertical  shear  is  distributed  over  a  sec- 
tion whose  area  is  the  width  of  the  stem,  that  is,  the  width  of  the  beam  multi- 
plied by  the  distance  from  the  center  of  the  steel  to  the  center  of  the  slab, 
the  latter  being  considered  as  approximately  the  center  of  compression.  In 
any  case  even  when  the  beam  is  reinforced  for  shear  the  unit  shear  stress  is 
limited  to  three-tenths  of  the  extreme  compressive  unit  fiber  stress.  Thus,  if 
the  allowable  compressive  fiber  stress  is  500  pounds  per  square  inch,  the  shear 
in  beams  not  reinforced  for  shear  must  not  exceed  50  pounds,  and  in  any  case 
the  section  must  be  large  enough  so  that  even  if  reinforced  there  is  sufficient 
area  of  concrete  to  keep  the  total  shear  stress  within  a  limit  of  150  pounds 
per  square  inch. 

When  all  of  the  shear  cannot  be  taken  by  the  concrete,  the  vertical  com- 
ponent of  the  diagonal  bent-up  tension  rods  is  figured  to  take  it,  and,  in  ad- 
dition, if  necessary  vertical  or  diagonal  stirrups  are  introduced. 

The  specifications  require  for  the  coarse  material  of  the  aggregate  trap 
stone  ranging  in  size  of  particles  from  }/\  inch  to  ij4  inches.  The  proportions 
for  the  floor  system  are  i  :2^  15,  or  by  exact  volume  one  barrel  (4  bags) 
cement  to  10  cubic  feet  sand  to  20  cubic  feet  stone. 

FLOOR  SURFACE. 

The  floors  are  all  finished  with  a  granolithic  surface  i  inch  in  thickness, 
and  this  is  included  as  a  part  of  the  slab  thickness.  Thus,  if  the  plans  require 
a  4-inch  slab  the  lower  three  inches  are  i  :2^  15  concrete,  and  the  top  inch  is 
granolithic.  The  granolithic  surface,  which  is  composed  of  one  part  cement 
to  i  part  sand  to  i  part  ^-inch  stone,  is  laid  before  the  concrete  below  it  has 
set,  so  as  to  form  one  homogeneous  slab. 

TEST  OF  FLOOR. 

At  an  age  of  thirty  days  it  is  specified  that  a  test  may  be  made  upon  the 
floor  panels  with  a  total  load  two  and  one-half  times  the  live  plus  the  dead 
load. 

COLUMNS. 

The  columns  are  spaced  12  feet  apart  lengthwise  of  the  building  and  17 
feet  9  inches  on  centers  across  the  building.  The  interior  columns  supporting 
the  lower  floors  are  24  by  24  inches  and  25  by  25  inches  (the  larger  size 
supporting  the  greater  spans),  and  in  the  three  upper  stories  the  sizes  are 
reduced  to  17  by  17  inches  and  18  by  18  inches.  This  arrangement  was  used 
to  avoid  remaking  the  column  forms,  this  saving,  in  the  opinion  of  the  build- 
ers, being  enough  to  more  than  offset  the  slight  excess  of  concrete  required. 

80 


8i 


The  columns  are  outlined  in  Fig.  27  (p.  79)  and  also  quite  distinctly  in 
the  general  cross-section  in  Fig.  25  (p.  76).  In  the  latter  the  diagonal  rods 
will  be  noticed  at  the  head  of  each  column  running  into  the  beams  and  pro- 
viding diagonal  reinforcement  against  wind  pressure.  The  building  is  so 
high  in  proportion  to  its  width  that  this  reinforcement  was  considered  ad- 
visable. 

The  ordinary  reinforcement  of  the  columns  is  four  ^-inch  vertical  rods, 
with  occasional  hoops  y$  inch  in  diameter.  In  the  wall  columns,  which  are 
oblong  in  plan  and  which  because  of  their  location  are  subjected  to  a  greater 
wind  pressure,  four  larger  vertical  rods  are  inserted.  The  rods  are  of  such 
length  as  to  project  above  the  next  floor  level,  and  the  next  set  rests  upon 
this  floor  so  as  to  lap  and  transfer  the  stresses. 

The  columns  are  laid  with  a  richer  concrete  than  other  parts  of  the  build- 
ing, being  mixed  in  proportions  1:1^2:3.  The  compressive  stress  allowed  is 
700  pounds  per  square  inch  figured  on  the  area  of  the  column,  or  600  pounds 
per  square  inch  on  the  concrete  if  the  steel  is  computed  to  take  a  proportion 
of  the  compression. 

CONSTRUCTION. 

Four  very  good  views  are  presented  in  Figs.  28,  29,  30,  31,  showing  the 
progress  from  the  first  story  to  the  stage  where  the  roof  is  laid  and  wall  panels 
are  nearly  completed. 

Fig.  28  (p.  81)  shows  the  first  story  columns  and  beam  molds  in  place, 
and  in  the  distance  the  setting  of  the  second-story  column  molds.  The  frame- 
work for  the  elevator  which  hoists  the  concrete  to  place  also  appears  on  the 
farther  side  of  the  building. 

Fig.  29  is  taken  after  the  completion  of  the  concrete  work  of  the  fifth 
floor.  The  forms  are  removed  from  the  columns  and  floor  of  the  lower  stories, 
but  the  supports  are  still  left  under  the  beams  and  girders  of  the  fourth  floor. 
The  wall  panels  are  completed  in  the  first  story  and  the  forms  for  the  second 
story  panels  are  in  place  on  the  side  of  the  building. 

The  view  in  Fig.  30  was  taken  when  the  building  was  one  story  higher, 
and  shows  more  clearly  the  elevator  for  hoisting  the  concrete,  the  mixer  being 
located  just  at  the  foot  of  it.  The  reinforcement  for  wall  panels  is  quite 
clearly  shown,  this  being  set  in  place  before  the  panel  forms  are  adjusted. 

Fig.  31  shows  the  building  with  the  roof  on  and  most  of  the  panel  work 
complete. 

A  photograph  of  the  building  complete  is  shown  in  Fig.  24  at  the  be- 
ginning of  the  chapter. 

The  construction  was  begun  about  July  i,  1906,  and  was  practically  com- 
plete December  ist,  although  the  cold  weather  caused  some  delay  beyond  this 
time  in  completing  the  panels.  The  average  rate  of  progress  on  the  forms 
and  structural  concrete  after  the  work  was  well  started  was  ten  days  per  story. 

82 


b) 


83 


Fig.  30.— Lynn  Storage  Warehouse  at  Sixth  Floor  Level.     (See  f.  te) 

84 


o 

J3 

<u 

I 

bJD 

2 

o 


C 

I 


W) 

£ 


85 


The  concrete  was  mixed  on  the  ground  in  a  rotary  mixer  (see  Fig.  30), 
and  a  hoist  elevated  the  concrete  and  dumped  it  into  the  hopper,  from  which 
it  was  conveyed  by  large  two-wheel  barrows  and  dumped  in  place.  Approxi- 
mately 2,000  cubic  yards  of  concrete  were  laid  in  the  structure  and  136  tons 
of  steel  were  used  in  the  reinforcement.  This  was  delivered  at  the  factory  of 
the  builders,  where  it  was  bent  to  the  shape  required,  the  ends  of  the  tension 
rods  being  also  bent  hot  at  right  angles  to  give  a  better  grip  in  the  concrete. 

In  placing  the  steel  the  stirrups  were  set  first,  and  as  these  were  in  the 
shape  of  a  U  with  the  ends  bent  over  on  a  curve,  these  ends  rested  upon  the 
slab  forms,  thus  forming  a  rest  for  the  tension  rods  which  were  placed  within 
them  and  supported  at  the  proper  distance  above  the  bottom  of  the  beam. 

FORMS. 

For  the  forms  spruce  lumber  was  generally  employed.  However,  a  good 
quality  of  North  Carolina  pine,  tongued  and  grooved,  was  used  for  the  panels, 
this  being  preferable  to  spruce  because  less  apt  to  warp  and  having  a  harder 
surface,  which  splinters  less  and  does  not  soak  so  much  water.  In  all  about 
182,000  feet  board  measure  of  lumber  were  used  in  the  construction  of  the 
building. 

Only  one  set  of  forms  was  required  above  the  first  floor,  the  forms  thus 
being  used  six  times.  Although  a  story  was  completed  on  the  average  in  ten 
days,  the  work  was  carried  on  from  end  to  end  of  the  building,  so  that  one 
end  of  the  floor  system  had  hardened  sufficiently  to  allow  removal  of  the  forms 
for  use  in  the  floor  above,  while  the  other  end  of  the  floor  was  being  laid. 
The  beams  and  girder  forms  were  constructed  as  U  units,  that  is,  the  sides 
and  bottom  were  fastened  together,  and  by  slightly  beveling  the  sides  the 
form  was  easily  lowered. 

By  reference  to  the  plan  in  Fig.  25  (p.  76)  it  will  be  seen  that  although 
the  allowable  loading  varied  on  different  floors,  the  dimensions  of  the  beams 
were  maintained  the  same  throughout  except  for  those  supporting  the  roof, 
the  difference  in  the  strength  being  provided  for  by  varying  the  reinforce- 
ment. 

The  general  plan  followed  in  removing  the  forms  was  to  leave  column 
forms  two  days,  slab  forms  six  days  and  beam  forms  six  days.  The  shoring 
however,  was  left  under  the  beams  and  girders  for  three  or  four  weeks  to 
guard  against  possibility  of  accident.  Of  course  these  periods  were  varied 
according  to  the  conditions  of  the  weather  and  the  hardening  of  the  concrete, 
but  they  represent  the  ordinary  minimum  time. 

Petrolatum  was  used  for  greasing  the  forms. 

The  usual  gang  consisted  of  one  superintendent,  3  foremen,  8  men  at  the 
mixing,  one  engineman,  12  men  placing  concrete,  3  steel  men  and  30  to  60 
carpenters,  the  larger  number  being  required  for  the  first  set-up  of  the  forms, 
while  the  smaller  number  was  sufficient  for  simply  raising  them  to  a  floor 
above  when  there  was  no  appreciable  change  in  the  design. 

86 


WALL  CONSTRUCTION. 

Panels  were  built  as  a  separate  operation  from  the  rest  of  the  concrete 
work,  as  shown  in  the  photographic  illustrations.  The  exterior  columns  were 
carried  up  at  the  same  time  as  the  floors,  and  the  wall  panels  afterward  filled 
in  between  them.  The  wall  panel  reinforcement  consisted  of  y2  inch  diameter 
rods,  the  horizontal  rods  being  spaced  12  inches  apart  and  the  vertical  rods 
24  inches  apart.  This  steel  was  first  placed,  as  shown  in  Figs.  29  and  30,  and 
after  setting  the  window  frames,  the  forms,  consisting  simply  of  2  inch  by  4 
inch  studs  with  i-inch  boards  nailed  to  them,  were  set,  and  the  concrete  pour- 
ed, running  into  grooves  left  in  the  columns.  In  Fig.  31  the  difference  in  the 
color  of  the  freshly  laid  and  the  old  concrete  is  apparent,  the  concrete  be- 
coming lighter  as  the  water  dried  out.  The  walls  were  completed  with  slap- 
dash or  stippled  finish,  illustrated  in  Fig.  129,  page  198. 

PARTITIONS. 

Around  the  elevators  and  stairs  and  also  to  enclose  the  offices  on  the 
first  floor  and  storage  rooms  on  the  fifth  floor,  expanded  metal  partitions  were 
employed.  Expanded  metal  lathing,  No.  24  gage,  was  wired  to  i-inch  channel 
bars  placed  vertically  12  inches  on  centers,  and  the  lathing  then  plastered 
with  five  coats  so  as  to  form  a  solid  partition  2  inches  thick. 

The  first  or  scratch  coat  consisted  of  one  part  cement  to  3  parts  of  lime 
with  the  usual  quantity  of  sand  and  hair.  This  pressed  through  the  lathing, 
so  that  it  could  be  plastered  on  both  sides  with  a  brown  coat  of  lime  and 
cement  mortar  in  proportions  i  part  cement  to  3  parts  of  lime  mortar  and  fol- 
lowed by  a  finishing  coat  of  the  same  mortar  on  both  sides. 

WATERPROOFING. 

To  meet  the  requirement  that  the  basement  should  be  very  dry,  asphal- 
tum  waterproofing  was  laid,  as  indicated  by  the  solid  black  line  in  Fig.  25 
(p.  76)  to  prevent  penetration  of  ground  water.  The  ground  having  been 
thoroughly  tamped,  a  layer  of  concrete  was  spread  upon  it  and  the  wall  slab 
placed.  Then  on  top  and  inside  of  this  layer  of  concrete,  five-ply  asphaltum 
waterproofing  was  spread  and  upon  this  3  inches  of  concrete  with  granolithic 
surface. 


88 


CHAPTER  VII. 


BULLOCK  ELECTRIC  MACHINE  SHOP. 

A  novel  feature  of  the  reinforced  concrete  machine  shop  of  the  Bullock 
Electric  Company,  at  Norwood,  Ohio,  a  branch  of  the  Allis  Chalmers  Com- 
pany, is  the  supporting  of  lo-ton  cranes  upon  concrete  brackets  which  form 
a  part  of  the  concrete  column.  It  is  customary  even  in  reinforced  concrete 
shops  to  place  the  crane  runs  upon  steel  columns  independent  of  the  rest  of 
the  structure,  but  we  have  here  an  example  of  the  transmission  of  the  load 
directly  from  the  runways,  which  are  steel  plate  girders,  to  the  reinforced 
concrete  columns.  The  machine  shop,  illustrated  in  Fig.  32,  was  only  fifty- 
eight  and  a  half  days  in  building  and  has  been  in  successful  and  continuous 
operation  since  its  completion  early  in  1906. 

The  building  under  consideration  is  an  extension  to  Shop  No.  3,  which 
is  of  the  regular  type  of  steel  frame  with  brick  walls.  The  extension  was 
first  designed  in  similar  steel  construction,  but  an  alternate  proposal  to  sub- 
stitute reinforced  concrete  made  by  the  Ferro  Concrete  Construction  Com- 
pany, of  Cincinnati,  was  adopted  at  substantially  the  same  cost. 

DESIGN. 

The  general  design  of  the  building  is  shown  in  the  cross-section  in  Fig. 
33,  and  a  partial  elevation  in  Fig.  34. 

The  lower  story  is  devoted  to  the  manufacture  of  the  heavier  part  of  the 
electric  machinery  and  in  the  assembling  of  dynamos.  In  the  upper  story 
are  the  lighter  machine  tools  for  the  making  of  the  smaller  parts.  The  roof 
is  of  2-inch  plank  upon  steel  trusses  (see  Fig.  33),  being  built  in  this  way  in- 
stead of  in  reinforced  concrete  so  that  it  can  be  raised  and  a  third  story  added 
when  needed.  One  end  of  the  building,  as  shown  in  the  photograph  of  the 
completed  shop,  Fig.  32,  is  also  of  temporary  construction,  so  that  it  can  be 
lengthened  without  tearing  down  a  brick  and  concrete  wall. 

Twisted  steel  was  used  for  reinforcement.  The  proportions  of  the  con- 
crete were  i  :2  14  throughout,  using  4  bags  Atlas  Portland  cement  to  8  cubic 
feet  of  good  coarse  sand  to  16  cubic  feet  of  broken  stone,  which  was  the  run  of 
the  crusher,  screened  through  a  i^-inch  screen. 

The  floors  (see  Fig.  33)  consist  of  three  longitudinal  bays  running  the 
entire  length  of  the  building,  a  distance  of  256  feet.  The  total  width  is  107 
feet  7J/2  inches,  thus  allowing  the  two  outer  bays  to  be  each  42  feet  njA 
inches  and  the  inside  bay  21  feet  Sll/2  inches.  In  the  other  direction,  that  is, 

89 


1 

Js* 


go 


lengthwise  of  the  building,  the  columns  are  16  feet  apart  on  centers.  The 
long  open  floor  spaces  afford  ample  room  for  the  machine  tools  and  the  hand- 
ling and  distributing  of  the  parts  and  the  finished  machines.  A  view  of  the 
shop  in  operation  is  photographed  in  Fig.  35. 

The  height  of  the  first  story,  27  feet  in  the  clear  from  the  floor  to  the 
ceiling  and  23  feet  in  the  clear  to  the  bottom  of  the  girders,  provides  the  head 
room  necessary  for  the  lo-ton  cranes  which  are  located  in  the  outside  bays, 
and  also  permits  very  large  high  windows. 

The  center  bay  is  designed  so  that  another  crane  may  be  installed  there 
when  required,  but  for  the  present  its  place  is  occupied  by  an  intermediate 
floor.  This  floor  is  of  light  steel  I-beam  and  wood  construction,  resting  upon 
channel  irons  running  across  between  the  two  rows  of  columns.  The  chan- 
nels are  bolted  at  the  ends  to  the  concrete  columns  and  their  weight  also  sup- 


Fig.  34. — Side  Elevation  of  the  Bullock  Machine  Shop.     (See  p.  5p.) 

ported  by  straps  suspended  from  the  crane  brackets.  Had  the  floor  been  in- 
tended for  permanent  use  it  would  have  been  built  of  reinforced  concrete,  but 
the  difficulty  and  expense  of  tearing  down  a  floor  of  concrete  when  the  space 
was  needed  for  the  crane  made  this  impracticable. 


c 

.2 

2 

<u 

o 

_£ 

I 

CO 

<u 
c 


bJD 


92 


COLUMNS. 

Footings  of  the  interior  columns  are  shown  in  Fig.  36.  These  illustrate 
a  typical  reinforced  concrete  footing  with  two  layers  of  rods  at  right  angles 
to  each  other  in  the  bottom.  In  this  case  the  rods  are  Y\  inch  diameter,  while 
in  the  footings  for  the  wall  columns,  which  are  not  shown  in  our  drawings, 


r         T  T 

1 1 H H 


-rr -r 


Fig.  36. — Reinforced  Footings  for  Interior  Columns.     (Sec  p.  93.) 

rods  fulfil  the  requirements.  The  rods  in  each  layer  are  shorter  than 
the  dimensions  of  the  footing  in  the  interior  columns  (Fig.  36),  being  6  feet 
8  inches  long  and  placed  with  one  end  2  inches  from  the  edge  of  the  footing 
and  the  other  end  18  inches  from  the  opposite  edge,  the  alternate  rods  being 
staggered  to  allow  for  the  decrease  in  the  bending  moment  from  the  column 
toward  the  edges  of  the  footing.  As  the  footing  is  square,  while  the  column 
is  oblong,  10  bars  run  in  one  direction,  while  12  bars  are  placed  in  the  other 
layer  to  provide  for  the  greater  bending  moment. 

The  footings  really  extend  up  to  within  3  inches  of  the  first  floor  level, 
the  short  vertical  section  of  2  feet  n  inches  being  built  at  the  same  time  as 
the  footing  proper  in  order  that  the  first  floor  can  be  laid  entire  and  the  first 

93 


story  columns  started  above  it.  These  short  vertical  lengths  are  reinforced 
with  six  i -inch  rods  which  extend  4  inches  down  into  the  main  part  of  the 
footing  and  project  7  inches  above  the  concrete  so  as  to  pass  through  the 
floor  and  connect  with  the  column  above.  These  vertical  rods  rest  upon  steel 
plates  3  inches  square,  which  distribute  the  compression  from  the  steel  to  the 
concrete.  Four  ^-inch  horizontal  hoops  are  placed  around  the  vertical  rods. 
The  columns  above  the  first  floor  are  of  slightly  smaller  dimensions,  as  shown 
by  the  offsets  in  Fig.  33.  Thus,  the  portion  below  the  first  floor  is  21  by  27 
inches,  which  reduces  to  18  by  24  inches  with  a  further  reduction  above  the 
crane  brackets.  The  reinforcement  in  the  columns  in  the  first  story  is  the 
same  as  below  the  floor,  six  i-inch  rods  butting  upon  the  ends  of  the  rods  be- 
low and  connected  with  them  by  a  short  pipe  sleeve.  One-quarter-inch  hoops 
were  spaced,  double,  every  12  inches. 

The  wall  columns  have  footings  similar  to  those  of  the  interior  columns, 
except  of  smaller  dimensions  and  lighter  reinforcement.  The  base  is  7  feet 
4  inches,  reinforced  with  sixteen  y2-mch  rods  in  each  layer.  Below  the  first 
floor  the  column  is  20  inches  by  26  inches,  reinforced  simply  with  a  ^-inch 
rod  in  each  corner  and  four  %-inch  horizontal  hoops. 

Above  the  first  floor  the  exterior  columns  are  of  T-shaped  cross-section, 
as  described  in  the  paragraphs  which  follow,  the  column  proper  being  14  by 
22  inches  in  the  first  story  and  12  by  14  inches  in  the  second  story. 

CRANE  BRACKETS. 

The  brackets,  shown  in  Fig.  33  (p.  90),  which  support  the  cranes  are  of 
particular  interest.  To  provide  for  the  shear,  it  was  considered  advisable  to 
loop  the  reinforcing  rods  into  the  bracket,  running  them  out  horizontally  and 
then  bending  them  down  on  an  incline  back  into  the  column.  The  steel  I- 
beams  supporting  the  track  for  the  crane  rest  directly  upon  these  brackets 
and  run  the  full  length  of  the  building. 

FLOOR  SYSTEM. 

The  floor  of  the  first  story  was  laid  directly  upon  the  ground  after  filling 
in  around  the  columns  and  thoroughly  puddling  the  earth.  This  floor  is  of 
1 12 14  concrete  with  sleepers  upon  it  and  a  2-inch  oak  floor. 

The  second  floor  is  supported  in  the  two  bays  by  girders  about  40  feet 
long  in  the  clear,  12  inches  wide  and  54^  inches  deep  from  top  of  slab.  In 
the  bottom  of  the  girder,  to  take  the  tension,  are  ten  i-inch  square  twisted 
rods  and,  to  provide  for  the  negative  bending  moment,  five  i-inch  rods  were 
placed  at  the  top  of  the  beams  over  the  supports.  The  shear  or  diagonal 
tension  is  provided  for  by  these  bent-up  rods,  together  with  sixteen  ^-inch 
and  ten  %-inch  U  bars.  The  reinforcement  was  rigidly  located  before  the 
concrete  was  poured,  so  that  it  could  not  be  displaced. 

In  the  central  bay  the  net  span  is  about  20  feet  and  the  girders  are  smal- 

94 


ler,  being  6  by  31  inches.  The  thickness  of  the  slab  is  included  in  the  depth 
of  the  girders  in  both  cases,  since  the  concrete  for  the  girders  and  slabs  was 
poured  at  one  operation. 

The  girders  extend  across  the  building  from  column  to  column,  and  are 
thus  1 6  feet  apart  on  centers,  giving  a  net  span  for  the  concrete  floor  slab  of 
15  feet  in  the  outside  bays  and  15  feet  6  inches  in  the  middle  bay.  The  slabs, 
which  are  designed  by  a  load  of  225  pounds  per  square  foot,  are  7%  inches 
thick,  reinforced  with  y2-inch  bars  spaced  6  inches  on  centers.  In  addition 
^4-inch  rods  about  2  feet  apart  run  across  the  building  parallel  to  the  girders 
to  prevent  contraction  cracks. 

The  wearing  surface  of  the  floor  is  /^-inch  maple  flooring  upon  3  by  4- 
inch  sleepers  spaced  16  feet  apart  on  centers  and  filled  between  with  cinder 
concrete. 

WALLS. 

The  window  area  comprises  a  large  percentage  of  the  wall  surface,  the 
openings  in  the  concrete  being  12  feet  2  inches  wide  and  in  the  lower  story 
23  feet  8  inches  high.  The  walls,  4  inches  in  thickness,  were  carried  up  at  the 


Fig.  37. — Tongs  for  Bending  Light  Steel  Bars.     (See  p.  96.) 

same  time  as  the  columns,  thus  forming  with  them  T-sections,  as  shown  in 
Section  GG,  Fig.  34.  Below  and  above  the  windows,  the  wall  was  also  4  inches 
thick,  with  water  table  and  sills,  as  in  Fig.  33.  The  window  sills,  which  are 
5  inches  thick,  were  poured  as  a  part  of  these  walls  and  were  thoroughly 

95 


troweled  on  the  top  before  the  concrete  had  set  hard,  so  as  to  form  a  surface 
like  that  on  a  sidewalk. 

Each  vertical  section  of  wall  was  reinforced  with  two  ^-inch  square  bars 
in  the  first  story  and  two  l/\. -inch  bars  in  the  second  story.  Horizontal  loops 
of  %-inch  wire  were  also  placed  about  2  feet  apart.  Above  the  windows  the 
walls  were  reinforced  with  three  horizontal  rods  and  with  vertical  rods  spaced 
about  3  feet  apart.  Fig.  34  (p.  91),  which  is  a  side  elevation  of  two  bays, 
illustrates  more  clearly  the  placing  of  the  wall  reinforcement. 

In  order  that  the  exterior  of  the  new  building  should  harmonize  with  the 
older  shops  in  the  same  plant,  the  walls  were  surfaced  with  a  single  thickness 
of  light-colored  pressed  brick.  These  were  tied  to  the  wall  by  the  wires  which 
were  used  in  keeping  the  forms  together.  These  ties  were  No.  8  galvanized 
iron  wire  about  12  inches  long,  which  projected  from  the  concrete  about  6 
inches.  They  were  spaced  every  18  inches  horizontally  and  every  six  courses 
of  brick  vertically.  The  projecting  ends  were  turned  in  a  hook  by  the  brick- 
layer and  bedded  in  the  mortar  joints  just  like  regular  brick  anchors. 

CONSTRUCTION  PLANT 

In  accordance  with  their  usual  plan  in  building  construction,  the  con- 
tractors erected  near  the  site  a  carpentry  shop  about  20  feet  by  42  feet,  with 


Fig.  38.— Power  Bender  for  Large  Steel  Bars.     (See  p.  98.) 

an  adjoining  tool  room.  In  the  shop,  wood  working  tools,  including  a  circular 
saw  and  a  planer,  were  installed  and  driven  by  electric  motor  from  power 
furnished  by  the  town  plant.  Here  all  the  forms  were  prepared. 

96 


97 


The  steel  was  also  bent  in  this  shop.  For  the  small  rods  of  the  floor  slabs 
a  heavy  pair  of  tongs  was  used,  with  three  projecting  lugs,  as  shown  in  Fig. 
37  (P-  95)-  The  heavy  steel  for  the  beams  and  girders  was  bent  by  power  in 
a  machine  consisting  essentially  of  a  face  plate  with  a  roller  projecting  from  it, 
which,  when  the  power  is  applied,  bends  the  bar  around  the  spindle.  The 
sketch  in  Fig.  38  (p.  96)  illustrates  the  operation. 

The  layout  of  the  construction  plant  and  its  relation  to  the  machine  shop 
are  illustrated  in  Fig.  39.  The  broken  stone,  sand  and  cement  were  brought 
in  railroad  cars  and  stored  in  bins  close  to  the  tracks.  The  mixing  plant  was 

tfor/zonfa/  5e,cf/or?  of  6/rtfer  Mou/ds 


Fig.  40.— Sectional  Plan  and  Elevation  of  Girder  Molds.     (See  p.  100.) 

provided  with  both  a  Ransome  and  a  Smith  mixer,  although  most  of  the  time 
one  of  these  machines  was  of  sufficient  capacity  to  supply  the  concrete.  The 
materials  were  wheeled  along  the  runway  on  the  platform,  from  which  they 
were  dumped  into  the  mixers.  From  the  mixers  the  concrete  was  brought  to 
the  place  where  used,  in  two-wheel  barrows  of  Ransome  type,  but  with  stag- 
gered wheel  spokes,  these  having  been  found  to  be  better  than  the  single  row 
of  spokes.  Each  of  these  held  about  5  or  6  cubic  feet  of  concrete.  The  hoist 
consisted  of  a  single  platform  double-barrow  hoist,  taking  two  barrows  up 
at  one  time,  and  from  the  hoist  the  concrete  was  wheeled  to  place  upon  a 
runway  raised  above  the  steel,  so  as  not  to  interfere  with  it,  and  dumped 
directly  in  place. 

The  cost  of  the  construction  plant,  not  including  small  tools,  shovels,  etc., 
was  $4,350.    In  the  building  2,300  barrels  of  cement  were  used. 


GANG. 

The  usual  gang  consisted  of  about  fifty  laborers  and  fifty  carpenters. 
The  men  engaged  directly  upon  the  building  were  distributed  approximately 
as  follows : 

Four  foremen. 

Twelve  men  mixing  concrete. 

Six  men  hoisting  concrete. 

Fifteen  men  placing  concrete. 

Seven  men  bending  and  placing  steel. 

One  engineman. 

Fifty  carpenters. 

The  regular  rate  of  pay  for  the  laborers,  who  were  experienced  concrete 
men,  was  $2  per  day  of  ten  hours. 


icf/or?  of  Column   Afou/d 


ra 


M?//ed  ?o  pane/ 


d/oc/c 


!jO7/E 


'fcoavX 


% 


Top  of 
floor-) 


3oac/'/?a  of  Co/umn 


Mou/d 


Fig.  41. — Details  of  Column  Molds.     (See  p.  /oo.) 

FORMS. 

The  forms  were  built  of  yellow  pine,  which  cost  $20  per  thousand.  As 
the  building  was  only  two  stories  high,  much  of  the  lumber  could  be  used  only 
once,  although  some  of  the  wall  and  column  forms  were  used  twice.  The 
lumber  cut  to  such  good  advantage,  however,  that  much  of  it  could  be  used  on 
another  job,  and  the  builders  estimated  the  salvage  at  about  30  per  cent.,  that 

99 


is,  it  might  be  assumed  that  three-fifths  of  the  lumber  could  be  used  to  good 
advantage  on  another  building,  and  that  the  value  of  this  was  one-half  of  its 
original  price. 

The  panel  boards  were  planed  one  side  and  on  the  edges.  For  the  beam 
and  column  molds  i  by  6-inch  tongued  and  grooved  stock  was  employed. 

The  construction  of  the  girder  molds  is  shown  in  Fig.  40  (p.  98),  and  the 
column  molds  more  in  detail  in  Fig.  41.  The  column  bands  or  clamps  were 
2  by  4-inch  stuff,  held  together  by  blocks  and  wedges,  as  shown  in  the  draw- 
ing. On  one  side  the  piece  was  loose,  so  that  the  same  clamp  could  be  used 
for  a  narrower  column  by  changing  the  position  of  the  blocks.  The  clamps 
were  spaced  18  inches  apart  near  the  bottom  of  the  column,  reducing  to  24 
inches  apart  near  the  top. 

The  girder  forms  consisted  essentially  of  i-inch  paneled  sides,  the  boards 
battened  together  with  pieces  of  2  by  4-inch  stuff,  and  a  bottom  of  i-j/J-inch 
plank,  which  was  supported  in  part  by  i  by  3-inch  cross  pieces  nailed  to  the 
end  of  the  batten  strips,  and  in  part  by  the  shores  or  struts  resting  upon  the 
floor  below.  A  i  by  6-inch  strip  nailed  to  the  upper  part  of  the  battens  sup- 
ported i  by  6-inch  joists,  upon  which  rested  the  slab  flooring. 

The  shores  or  struts,  instead  of  being  a  single  piece  of  lumber,  were 
made  of  I-section  by  nailing  together  three  pieces  of  2  by  6-inch  plank,  as 
shown  in  section  AA,  Fig.  40.  This  plan  was  followed  because  the  first  story 
was  so  high  that  an  ordinary  4  by  4-inch  post  would  have  been  liable  to  spring 
unless  braced  very  frequently  in  its  height.  An  exterior  view  of  the  building 
during  construction,  showing  the  column  and  girder  forms  and  bracing,  is 
given  in  Fig.  42. 

The  forms  of  the  walls,  columns  and  panels  were  left  in  place  about  two 
weeks  and  the  shores  six  weeks.  This  time  was  longer  than  is  customary, 
but  in  this  building  the  spans  were  so  long  that  the  dead  weight  of  the  con- 
crete was  exceptionally  large,  and  this  threw  a  large  proportion  of  the  total 
load  upon  the  concrete  when  the  forms  were  first  taken  down. 


100 


o 

fa 

W) 

c 


o 
c/3 

-a 

2 

bfl 
O 

•4-1 

I 


bfl 
fa 


101 


102 


CHAPTER  VIII. 


WHOLESALE  MERCHANTS'  WAREHOUSE. 

The  immense  reinforced  concrete  warehouse  at  Nashville,  Tenn.,  illustra- 
ted on  the  opposite  page,  is  the  result  of  a  scheme  of  co-operation  of  a  number 
of  the  most  prominent  merchants  of  that  city.  They  previously  had  con- 
ducted their  business  in  various  individual  warehouses  in  the  business  sec- 
tion of  the  city  and  some  distance  from  the  railroad.  To  better  their  condi- 
tion the  idea  was  conceived  of  forming  the  Wholesale  Merchants'  Warehouse 
Company  to  erect  a  fireproof  building  alongside  of  the  tracks,  and  thus  save 
the  large  expense  of  hauling  and  at  the  same  time  obtain  greatly  reduced 
insurance  rates. 

Insurance  on  the  stock  carried  by  the  merchants  in  the  old  type  of  frame 
buildings  ranged  from  $1.80  to  $2.20  per  hundred  while  in  the  new  fireproof, 
reinforced  concrete  structure  the  rates  were  reduced  to  $0.40  per  hundred. 

To  provide  enough  floor  space  not  only  for  storage  but  also  for  carrying 
on  the  wholesale  shipments,  the  building  is  500  feet  long  by  132  feet  deep 
and  four  stories  high,  with  basement  and  sub-basement.  It  is  divided  by 
walls  of  concrete  blocks  into  compartments  entirely  separate  one  from  the 
other,  each  compartment  comprising  a  complete  wholesale  warehouse,  and 
as  the  building  is  located  not  only  near  the  railroad  but  in  the  central  part  of 
the  city  as  well,  it  constitutes  the  sole  place  of  business  in  the  city  for  each 
firm. 

The  basement  is  paralleled  by  two  railroad  tracks,  an  extension  of  the 
basement  floor  forming  the  unloading  platform.  A  wide  trucking  platform 
also  runs  through  the  basement,  reaching  all  the  elevators. 

Reinforced  concrete  was  adopted  because  of  the  estimated  economy  in 
cost  and  in  time  of  construction.  The  designing  architects  were  Messrs.  Mc- 
Donald &  Dodd;  the  supervising  architect,  Mr.  Hunter  McDonald,  and  the 
engineer,  Mr.  W.  H.  Burk.  The  Oliver  Company  were  the  builders. 

Corrugated  bars*  were  used  throughout  the  building,  and  the  Expanded 
Metal  and  Corrugated  Bar  Company  approved  the  plans  as  drawn. 

LAYOUT. 

The  general  plan,  Fig.  44  (p.  105),  is  a  framing  plan  showing  the  layout 
of  the  beams  and  also  illustrating  the  division  of  one  of  the  floors  into  the 
compartments  for  the  different  firms.  The  interior  columns  are  spaced  12  feet 

*  See  Fig.    103,  page   179. 

103 


apart  in  one  direction  and  16  feet  7^  inches  in  the  other.  In  general,  the 
beams  run  lengthwise  of  the  building  from  column  to  column,  with  no  sup- 
porting girders,  while  cross  beams  are  placed  at  intervals  to  tie  the  building 
together  and  to  support  the  partitions. 

These  cross  beams  and  their  partitions  are  not  spaced  uniformly,  but  at 
different  distances  apart,  so  as  to  afford  a  merchant  a  choice  of  several  sizes 
of  rooms,  each  of  which  extends  the  full  depth  of  the  building.  For  example, 
the  spacing  of  the  partitions  is  three  bays  in  a  large  number  of  cases,  while 
in  one  portion  of  the  building  the  spacing  is  one  and  a  half  bays ;  in  another, 
two  bays;  and  in  still  another  four  bays.  The  widths  of  the  compartments 
thus  vary  from  about  24  feet  to  66  feet,  with  a  uniform  depth  of  about  130 
feet. 

The  beam  design  is  somewhat  different  from  usual  along  the  front  and 
rear  of  the  building.  Here  the  cross  span  is  18  feet  instead  of  12  feet,  and 
short  cross  girders  are  introduced,  each  of  which  supports  a  floor  beam  at  its 
center.  The  projecting  girders  at  the  rear  of  the  building,  that  is,  at  the  top 
of  the  plan  in  the  figure,  support  the  roof  over  the  loading  platform  in  the 
basement. 

A  cross  section  of  the  building  is  given  in  Fig.  45  (p.  106),  showing  the 
columns  and  the  outline  of  the  beams  and  slabs.  In  order  to  take  advantage 
of  the  full  width  of  the  lot,  and  yet  not  encroach  upon  the  loading  platform 
with  the  basement  columns,  the  rear  wall  of  the  building  from  the  first  floor 
up  to  the  roof  is  supported  by  the  ends  of  the  floor  girders  which  project  at 
each  story  about  30  inches,  thus  acting  as  cantilevers. 

Because  of  the  variety  in  the  weights  of  the  goods  to  be  stored,  the  floors 
were  designed  for  different  loadings.  The  first  floor  was  calculated  for  350 
pounds  loading  per  square  foot  of  surface,  the  second  floor  for  300  pounds 
and  the  third  and  fourth  floors  for  250  pounds.  The  roof  was  figured  for  a 
snow  load  of  40  pounds  per  square  foot.  These  figures  in  each  case  represent 
live  loads,  and  do  not  include  the  weight  of  the  concrete  itself. 

BEAMS  AND  SLABS. 

Details  of  the  construction  of  a  typical  beam  and  slab  are  drawn  in  Fig. 
46  (p.  107).  These  are  designed  for  the  first  story  to  support  a  floor  load  of 
350  pounds  per  square  foot  in  addition  to  the  weight  of  the  reinforced  con- 
crete itself. 

Inspection  of  the  plans  shows  that  three  of  the  six  bars  in  the  beam  are 
bent  up  on  an  incline  and  run  across  over  the  supports,  lapping  there  a  dis- 
tance of  one-quarter  of  the  span  length.  Several  3/i6-inch  round  stirrups 
are  also  provided  to  assist  in  taking  the  shear.  The  dimensions  of  the  beams, 
12  by  20  inches  for  the  longitudinal  beams  of  which  the  details  are  shown, 
and  10  by  1 6  inches  for  the  cross  beams  supporting  the  partitions,  are  given 
in  the  customary  way,  measuring  the  depth  from  the  top  of  the  slab  to  the 
bottom  of  the  beam,  and  assuming,  of  course,  that  the  standard  practice  is 

104 


V 


a. 
»0bA 


9t/r?  &f/P//n0-^ 


JJ 


^ 

h  £ 


105 


CTJ 


bfl 

fe 


106 


followed  of  placing  the  concrete  in  the  beams  and  slabs  at  one  time,  so  as  to 
form  a  monolithic  T-section.  The  rods  in  the  bottom  of  the  beam  are  placed 
in  two  layers,  so  as  to  bring  them  far  enough  apart  to  prevent  the  concrete 
splitting  between  them. 

It  will  be  noticed  in  the  floor  sketched,  that  ^-inch  bars  5  inches  apart 
to  form  the  reinforcement  for  the  slab,  are  placed  in  the  bottom  of  the  slab 
at  the  center  of  its  span,  but  that  all  run  up  toward  the  supporting  beam,  and 
thus  in  the  longitudinal  section  of  the  beam  at  the  top  of  the  diagram  these 
rods,  which  are  shown  by  so  many  dots,  are  close  to  the  upper  surface.  This 
plan  is  somwhat  easier  to  follow  than  where  rods  are  alternately  horizontal 
and  bent  up,  and  it  is  preferable  to  the  latter  because  the  negative  bending 
moment  at  the  ends  of  a  continuous  slab  is  at  least  as  great  as  the  positive 
moment  in  the  center,  so  that  fully  as  much  reinforcement  is  required  to  take 
the  pull  at  the  top  of  the  slab  over  the  supports  as  is  necessary  in  the  bottom 
at  the  middle  of  the  span. 

The  roof  is  of  concrete  of  lighter  design,  and  the  slab,  which  is  3  inches 
thick,  is  laid  on  a  slope  of  ^/J-inch  per  foot  and  is  covered  with  tar  and  gravel 
roofing. 

A  detail  of  the  beams  around  elevator  walls  is  drawn  in  Fig.  47. 


-non  or  TYP/GAL  BEAM  in  h/csr  FLOP/?  (/2"x2O')<l 


SECT/OH  OF  TYHCAL  few  AHD  SLAB 


Fig.  46. — Details  cf  Reinforcement  of  Typical  Beam  and  Slab.     (5V<?  />.  104.) 

COLUMNS. 

Although  the  floor  loads  are  heavy,  the  columns  are  only  19  inches  square 
in  the  basement  and  less  than  this  in  the  stories  above  because  the  spacing 
between  them  is  comparatively  small.  The  general  type  of  reinforcement  is 
four  5/g-mch  vertical  bars  near  the  corners  with  3/1 6-inch  horizontal  loops  at 
intervals  of  5  to  12  inches,  varying  with  the  dimensions  of  the  columns.  In 
the  first  story  }/ -inch  vertical  bars  were  used  with  loops  4  inches  apart. 

The  columns  are  designed  for  a  loading  of  750  pounds  per  square  inch, 
a  seemingly  high  stress  for  the  proportions  of  cement  to  aggregate  used,  i : 
2/4:4/^»  but  in  making  the  calculations  no  account  is  taken  of  the  area  of 
concrete  outside  of  the  steel  loops  nor  of  the  strength  of  the  vertical  steel,  so 
that  the  loading  is  really  conservative. 

107 


WALLS. 

For  the  walls  a  skeleton  structure  of  columns  and  beams  is  carried  up, 
as  shown  in  the  photographs,  and  filled  in  with  brickwork,  the  outside  face 
of  the  columns  being  veneered  with  brick  so  as  to  give  a  uniform  surface. 
The  exterior  trimmings  and  the  doors  and  widow  sills  are  all  artificial  stone. 

The  interior  or  partition  walls,  which  separate  the  compartments  into 
which  the  floors  are  divided,  are  of  concrete  blocks  supported  upon  reinforced 
beams. 


FREIGHT  ELE.VATOE 


Fig.  47.— Detail  of  Framing  at  Elevator.     (See  p.  108.) 

The  concrete  blocks  were  made  of  i  part  cement  to  1^2  part  sand  to  4^2 
part  crusher  dust.  They  were  made  in  Hercules  facedown  machines  and 
were  faced  on  both  sides  during  the  process  of  the  making  with  a  layer  of 
i  to  2,%  mortar.  The  standard  size  blocks  in  the  partition  walls  were  8  by  8 
by  24  inches,  with  two  hollow  spaces ;  the  blocks  around  the  elevators  were  4 
by  4  by  6  inches  solid.  Rabbets  were  formed  in  each  end  and  in  top  and  bottom 
surfaces,  and  filled  with  cement  mortar  as  the  blocks  were  laid,  in  order  to 
secure  as  perfect  a  bond  as  possible.  No  interior  plastering  was  used  in  the 

108 


building  except  in  the  offices  of  each  warehouse,  which  usually  occupied  only 
a  small  part  of  the  first  floor.  The  first  two  floors  of  the  building  outside  of 
the  offices  were  whitewashed  by  machines.  The  rest  was  left  without  any 
finish. 

STAIRS. 

Stair  details  are  shown  in  Fig.  48.  The  stairways  are  of  straight  run 
from  story  to  story,  and  consist  of  a  slab  with  the  upper  surface  formed  into 
steps.  The  bottom  of  the  slab  is  reinforced  with  ^-inch  bars  placed  2  inches 
apart,  and  ^-inch  rods  also  run  across  the  steps  at  occasional  intervals.  The 
foot  and  head  of  each  flight  is  especially  reinforced,  as  shown,  to  strengthen 
it  at  the  ends  and  connect  it  with  the  floor  system. 

COAL  TRESTLE. 

Reinforced  concrete  coal  trestles  are  occasionally  built,  but  comparatively 
few  designs  have  been  published,  and  the  trestle  erected  in  connection  with 
this  building  is  therefore  shown  in  considerable  detail.  Its  elevation  is  given 
in  Fig.  45  (p.  106)  and  the  details  in  Fig.  49. 

Two  railroad  tracks  are  carried  by  the  trestle  and  most  of  the  surface  is 
floored  over,  the  slabs  being  sloped  to  drains. 


Fig.  48.— Details   of   Stairs.      (See  p.  /op.) 


CONSTRUCTION. 

The  warehouse  was  about  eight  months  in  building,  and  during  this  period 
11,830  cubic  yards  of  concrete  were  placed;  of  this  8,398  cubic  yards  were  re- 
inforced and  3,432  cubic  yards  plain.  The  latter  figures  included  the  blocks. 
The  mortar  finish  for  the  floors  measured  in  addition  510  cubic  yards. 

Amount  of  cement  required  was  as  follows : 

109 


Reinforced  concrete,  10,365  barrels. 
Floor  finish,  1,690  barrels. 
Artificial  stone,  99  barrels. 
Plain  concrete,  1,770  barrels. 
Concrete  blocks,  4,051  barrels. 
Total,  17,975  barrels. 

The  work  in  progress  is  shown  in  photographs,  Figs.  50  and  51.  These 
were  taken  on  the  same  date,  but  from  different  points  of  view,  the  former 


& 


fists'  C&JCfiefc  Cap  on 

I  //&/«*  //g/» 


I  /a/* 


Fig.  49.—  Details  of  Coal  Trestle.      (See  p.  /op.) 

from  the  rear  of  the  building  next  to  the  railroad  track  and  the  latter  from  the 
unfinished  end,  showing  also  the  front  in  process  of  construction. 

The  concrete  was  supplied  to  the  different  parts  of  the  building  by  a 
cableway  which  is  clearly  seen  in  Fig.  50. 

The  cable  was  supported  by  the  two  towers  located  at  each  end  of  the 


no 


o 
O 

bJD 

.s 

Q 


III 


bfl 


112 


I* 


bfl 


building  and  far  enough  away  from  it  to  leave  room  for  the  construction  plant 
between. 

The  outline  of  the  building  with  the  cableway  and  construction  plant  is 
sketched  in  Fig.  52.  The  building  rests  on  ledge,  so  that  it  was  necessary  to 
excavate  a  large  quantity  of  rock,  and  the  stone  taken  out  was  utilized  in  the 
concrete  and  also  in  the  concrete  blocks.  This  necessitated  the  installation 
of  a  crushing  plant,  a  somewhat  unusual  feature  in  building  construction,  but 
which  was  made  possible  by  the  large  amount  of  ground  space  and  by  the  fact 
that  the  broken  stone  and  screenings  not  only  could  be  utilized  for  the  build- 
ing, but  because  there  was  a  demand  for  the  sale  of  the  surplus  coarse  mate- 
rial for  railroad  ballast. 

Crushers  were  set  to  crush  the  stone  to  maximum  size  of  i  y2  inch  and  the 
dust  up  to  ^4-inch  was  screened  out  for  use  in  the  concrete  blocks.  All  the 
rest  of  the  crushed  material  was  used  in  the  concrete  without  further  grading. 
Sand  used  on  the  work  was  brought  in  from  Memphis  in  cars,  while  for  the 
floor  finish  the  aggregate  was  crushed  granite. 

A  No.  4  Smith  mixer  made  the  concrete,  and  this  was  fed  with  material 
by  a  stiff-legged  derrick  having  a  65-foot  boom  and  operated  by  a  4-drum 
Lambert  engine.  The  bucket  was  of  a  ij/^-yard  clamshell  type,  and  dumped 
the  material  into  charging  bins  which  measured  the  materials  automatically. 
The  concrete  fell  from  the  mixer  into  buckets  which  were  taken  by  cable  and 
transported  to  steel  portable  bins  located  on  the  floor  of  the  building  where 
the  concrete  was  laid,  and  whence  it  was  finally  delivered  by  Ransome  2-wheel 
carts.  The  highest  run  of  the  plant  was  383  cubic  yards  in  ten  hours.  A 
diagram  of  the  mixing  plant  is  given  in  Fig.  53. 

The  cableway  also  handled  lumber  for  the  forms  and  mortar  for  the  floor 
finish,  which  was  put  on  as  the  concrete  was  laid. 

The  plan  of  the  plant  also  locates  the  lumber  yard  and  carpenter  shop 
at  the  other  end  of  the  building  from  the  concrete  plant.  The  forms  were  all 
made  here,  as  much  of  the  work  as  possible  being  done  by  machinery. 

The  cost  of  the  lumber  for  the  forms,  which  were  used  from  four  to  eight 
times,  was  $5,400  and  the  salvage  is  figured  at  about  20  per  cent.,  i.  e.,  it  is 
estimated  that  the  value  of  the  lumber  left  over  which  would  be  suitable  for 
another  job  was  about  20  per  cent,  of  the  original  cost  or  about  $1,100  and 
that  this  amount  could  be  deducted  when  charging  up  the  lumber  to  this 
building.  Pine  lumber  was  used  throughout,  and  for  panels  it  was  tongued- 
and-grooved.  The  forms  were  left  in  place  for  about  25  days. 

At  one  end  of  the  building  all  of  the  reinforcement  was  stored,  and  forges 
operated  by  compressed  air  from  the  signal  plant  of  the  N.  C.  &  St.  L.  Ry. 
were  so  arranged  that  they  could  be  set  at  required  points  and  the  girder  bars 
which  required  bending  thus  heated  and  bent  in  four  places  at  the  same  time. 
Special  benders  were  used  for  shaping  the  small  rods.  The  column  reinforce- 
ment was  assembled  and  wired  together  before  being  placed  in  the  form, 
special  care  being  taken  to  accurately  place  it.  The  cost  of  bending  and  plac- 
ing the  steel  was  0.4  cents  per  pound. 

114 


\          L- 


(a) 


Fig.  53.— Mixing  Plant.     (See  p. 


\ 


116 


bfi 


The  construction  gang  consisted  in  general  of  three  foremen,  3  men  mix- 
ing, 32  men  placing,  45  carpenters,  20  steel  men,  9  enginemen,  besides  some 
60  to  150  men  on  the  excavation  and  from  10  to  40  men  on  the  stone  crushing. 

A  photograph  of  the  interior,  showing  the  columns  and  floor  system,  is 
given  in  Fig.  54. 

COST. 

The  entire  cost  of  the  building  was  about  $357,000  including  finish,  of 
which  $192,000  was  for  the  reinforced  concrete  and  the  excavation.  The  cost 
of  the  construction  plant,  which  is  included  in  these  sums,  was  "$19,000,  an 
unusually  large  amount,  but  probably  warranted  in  this  case  by  the  size  of 
the  building  and  the  need  of  a  crusher  plant. 


117 


bb 

£ 


118 


CHAPTER  IX. 


BUSH  MODEL  FACTORY. 

The  plant  of  the  Bush  Terminal  Company,  located  in  South  Brooklyn 
on  the  east  shore  of  New  York  Bay  on  Thirty-sixth  street,  between  Second 
and  Third  avenues,  will  cover  when  completed  an  immense  area  and  comprise 
some  hundred  and  fifty  warehouses  and  factories.  Many  of  the  more  recent 
of  these  buildings  are  of  reinforced  concrete  construction,  the  factory  selected 
from  this  group  for  description  being  75  ft.  wide  by  599  ft.  long,  and  six 
stories  high  above  the  basement.  Several  features  of  the  design  are  of  un- 
usual types. 

The  Terminal  Company  owns  some  160  acres  of  land  with  nearly  three- 
quarters  of  a  mile  of  water  front.  A  number  of  piers,  each  one-quarter  of  a 
mile  in  length,  with  wide  docks  between,  permit  the  largest  ocean  steamers 
to  discharge  and  load  without  interference.  The  large  warehouses,  50  by 
150  feet,  and  from  four  to  seven  stories  high,  provide  the  steamship  lines 
renting  the  piers  with  unusual  facilities  for  both  storage  and  trans-shipment 
of  freight. 

In  addition  to  this  storage  and  shipping  business  handled  by  the  piers 
and  warehouses,  a  plan  is  already  being  carried  out  to  erect  eighteen  fireproof 
factories  or  loft  buildings,  their  floor  space  to  be  rented  for  manufacturing 
purposes.  The  first  of  these  factories,  built  in  1905,  and  the  second,  called 
the  Bush  Model  Factory  No.  2,  built  in  1906,  offer  unusually  attractive  fea- 
tures because  of  the  excellent  facilities  afforded.  The  details  of  the  latter, 
which  is  shown  complete  in  Fig.  55,  form  the  subject  of  this  chapter. 

The  builder  of  this  concrete  factory  was  the  Turner  Construction  Com- 
pany. Mr.  E.  P.  Goodrich,  formerly  chief  engineer  for  the  Bush  Terminal 
Company,  prepared  the  structural  design,  and  Mr.  William  Higginson  was 
the  architect. 

DESIGN. 

Instead  of  the  usual  system  of  beams,  girders  and  slabs,  the  floors  consist 
essentially  of  heavy  girders  directly  supporting  ribbed  slabs,  designed  so  that 
the  under  surface  presents  a  corrugated  or  ribbed  appearance,  the  purpose 
being  to  use  for  the  necessarily  long  spans  a  minimum  quantity  of  concrete, 
placed  most  effectively  to  take  the  loads  upon  it. 

An  idea  of  the  general  plan  of  the  structure  is  gained  from  Fig.  56.  In 
order  to  present  it  on  a  fairly  large  scale,  only  one  end  of  the  building,  a 
length  of  about  225  feet  in  a  total  of  599  feet,  is  shown. 

119 


120 


..  Cross -Sec  f /or? Cro35-*5ect/o/7 

~WZ7oof& 


Fig.  57. — Sectional  Elevation  of  Bush  Factory  No.  2.      (See  p.  119.} 


121 


The  sectional  elevation  may  be  seen  in  Fig.  57. 

Two  lines  of  columns  16  ft.  7  in.  on  centers  divide  the  factory  into  aisles 
about  24  ft.  in  width,  thus  giving  exceptionally  good  floor  space  for  either 
storage  or  manufacturing.  Heavy  girders  run  lengthwise  of  the  building 
from  column  to  column,  while  spanning  the  distance  between  these  two  lines 
or  girders  and  the  walls  is  the  ribbed  floor  system. 

Two  groups  of  four  elevators  each  are  located  one-quarter  way  from  each 
end  of  the  building,  and  in  adjoining  bays  on  each  side  of  both  groups  of  ele- 
vators are  the  stair  wells.  The  first  floor  plan,  Fig  56  (p.  120),  shows  the 
stairs  to  the  basement  only  on  one  side  of  the  elevators,  but  an  additional 
flight  is  provided  for  the  stories  above.  Except  for  the  location  of  the  stairs, 
the  floor  system  of  the  different  stories  is  identical,  thus  simplifying  the  de- 
sign and  permitting  the  use  of  the  same  forms  throughout. 

The  roof  is  surrounded  by  a  fire  wall  3  feet  6  inches  high.  A  series  of 
skylights  over  the  center  aisle  afford  additional  light  to  the  top  story. 

Round  rods  formed  into  trusses  on  the  ground  and  raised  to  place  ready 
to  drop  into  the  forms  provide  the  reinforcement.  The  proportions  of  the  con- 
crete used  throughout  were  one  part  Portland  cement,  2  parts  sand,  4  parts 
stone,  being  equivalent  in  actual  volume  to  one  barrel  (4  bags)  cement,  7.2 
cubic  feet  of  sand,  and  14.4  cubic  feet  of  broken  stone.  The  aggregate  con- 
sisted of  sand  excavated  by  dredges  from  Cowe  Bay,  and  washed  gravel  of  a 
size  passing  a  ^4 -inch  sieve. 

COLUMNS. 

The  column  footings  are  supported  by  wooden  piles,  and  the  area  of  the 
footing  is  so  large  in  proportion  to  the  size  of  the  columns  as  to  require  a 
special  design  of  heavy  horizontal  rods  and  vertical  stirrups. 

In  Factory  No.  i  the  interior  columns  are  cylindrical  and  composed  of 
an  outside  shell  of  cinder  concrete  2^  inches  thick.  These  cinder  concrete 
cylinders  were  prepared  in  advance  in  2-foot  lengths  in  a  zinc  mold,  with 
spiral  hooping  and  expanded  metal  forming  the  inner  surface.  After  harden- 
ing, they  were  set  one  upon  another  in  the  building,  and  filled  with  concrete. 

In  Factory  No.  2  the  columns  are  octagonal  in  shape,  and  composed 
wholly  of  gravel  concrete.  Just  below  the  girders  the  section  was  made 
square  (see  Figs.  56  and  57),  these  square  caps  being  of  the  same  size  on  all 
the  stories  so  as  to  avoid  altering  the  rib  and  girder  molds. 

The  columns  were  spirally  reinforced  with  round  high  carbon  steel  ft  to 
l/2.  inch  in  diameter,  the  pitch  varying  in  the  different  stories.  The  loading 
upon  the  columns  was  graduated  from  500  pounds  per  square  inch  of  their 
section  for  the  upper  floor  to  1,000  pounds  per  square  inch  in  the  basement. 
This,  however,  assumed  full  loads  on  all  the  floors  at  the  same  time,  which 
would  not  ordinarily  occur,  so  that  the  columns  in  the  lower  stories  are  liable 
to  be  stressed  much  less  than  the  nominal  figures.  The  spiral  hooping  is 
computed  to  assist  in  bearing  the  load. 

122 


FLOOR  SYSTEM. 

The  general  scheme  of  design  has  been  referred  to  in  paragraphs  above. 
Longitudinal  girders  of  13  feet  4  inches  net  span,  supported  by  columns  16 
feet  7  inches  on  centers,  carry  the  ribbed  slabs  which  run  across  the  building 
with  a  net  span  of  about  23  feet. 

The  details  of  design  of  the  beams  and  ribbed  slabs  are  drawn  in  Fig. 
58.  The  ribs  are  V-shaped  in  cross-section,  as  shown  in  Sections  aa  and  bb. 
Two  i -inch  round  rods,  one  bent  up  at  the  points  determined  by  moment  dia- 
gram, and  the  other  extending  horizontally  to  the  girders,  provide  for  the 
tension,  and  %-inch  stirrups  are  bent  around  and  wired  on  to  the  horizontal 
rods.  Ribs  A,  which  are  shown  in  the  diagram,  connect  the  two  girders, 
while  ribs  B,  which  run  from  the  girders  to  each  wall,  are  similar  in  design 
except  that  the  upper  rod  cannot  project  beyond  the  support,  and  is  therefore 
anchored  by  bending  it  with  a  quarter  turn  around  another  rod  which  runs 
at  right  angles  to  it  in  the  wall. 

The  steel  is  designed  for  a  maximum  pull  of  16,000  pounds  per  square 
inch  when  the  full  allowed  load  is  on  the  floor,  and  stirrups  are  provided 
wherever  the  shear  exceeds  50  pounds  per  square  inch.  The  floors  are  de- 
signed for  a  loading  of  200  pounds  per  square  foot  besides  the  dead  weight 
of  the  concrete. 

The  design  of  the  principal  girders  is  also  shown  in  Fig.  58.  The  stirrups 
are  close  together  at  the  ends  of  the  girders  where  the  shear  is  the  greatest, 
and  each  stirrup  is  looped  around  the  tension  rods,  then  passes  up  on  each 
side  of  the  girder  and  across,  as  shown  in  the  sections.  The  stirrups  are  J^- 
inch  in  diameter  near  the  end  of  the  beam,  then  at  the  points  where  the  large 
rods  are  inclined  and  thus  take  a  portion  of  the  shear,  the  size  is  reduced  to 
5/1 6  inch,  and  this  is  continued  to  the  center  of  the  beam,  the  spacing  grad- 
ually becoming  wider  as  the  shear  decreases.  The  tensional  reinforcement 
in  the  girders  consists  of  four  i^-inch  rods,  two  of  which  are  bent  up  just 
beyond  the  one-quarter  points,  and  extend  nearly  to  the  center  of  the  column, 
where  each  is  connected  with  the  reinforcement  in  the  next  girder  by  an  oval 
link  of  %  inch  round  steel. 

In  the  bays  around  the  elevators,  the  rib  forms  were  dropped  Sy2l  inches, 
so  as  to  make  the  slabs  between  the  ribs  12  inches  thick,  as  shown  in  Section 
CC,  Fig.  56. 

No  reinforcement  was  placed  longitudinally  of  the  building  at  right 
angles  to  the  ribs.  In  the  floors  first  laid  with  the  V-shaped  rib,  slight  shrink- 
age cracks  occurred  between  the  ribs  and  parallel  to  them.  These,  however, 
did  not  open  or  indicate  any  structural  weakness,  and  they  were  eliminated 
by  more  thorough  roding  of  the  surface. 

The  underside  of  the  floor  construction,  and  also  the  columns,  are  shown 
in  the  photograph,  Fig.  59  (p.  126). 

The  reinforcement  was  according  to  the  Bertine  Unit  Girder  Frame  sys- 
tem as  modified  by  Mr.  Goodrich.  This  work  of  bending  and  placing  was 

123 


124 


performed  under  a  separate  contract  by  Mr.  M.  S.  Hamsley  in  an  open  shed 
near  the  building.  To  the  wooden  posts  supporting  the  roof  of  the  shed, 
brackets  were  fastened  at  the  exact  locations  to  support  the  horizontal  and 
the  bent-up  rods  of  the  truss.  These  principal  members  were  bent  in  the 
special  bending  machine  provided  for  the  purpose,  then  were  brought  to  the 
shed  and  hung  upon  the  brackets,  when  the  stirrups  were  sprung  upon  them, 
and  wired  to  the  large  rods  by  ordinary  stove  pipe  wire.  The  system  of  rods 
for  each  rib  or  girder  thus  formed  a  truss,  as  shown  in  Fig.  58,  and  was  taken 
by  the  general  contractors,  elevated  to  the  floor  where  it  was  to  be  used,  and 
dropped  into  the  form.  The  girder  frame  or  truss  rested  upon  blocks  of  con- 
crete placed  in  the  bottom  of  the  form,  and  the  rib  truss  was  held  upright  by 
wiring  each  end  to  the  steel  in  the  girder  truss. 

On  the  girder  trusses,  four  men  worked  in  a  gang,  and  could  put  together, 
after  the  large  rods  were  bent,  from  twenty-five  to  thirty  frames  per  day. 

The  spirals  for  the  column  reinforcement  in  Factory  No.  i  were  formed 
around  a  horizontal  skeleton  drum  by  two  men  who*  wound  the  ^J-inch  wire 
around  it  and  wired  it  to  the  ^-inch  longitudinal  rods.  In  Factory  No.  2  a 
special  machine  was  used  for  bending. 

WALLS. 

The  walls  consist  essentially  of  glass  between  concrete  columns.  The 
window  lintels  are  reinforced  concrete  beams  and  above  the  floor  level  8-inch 
walls  were  carried  up  from  the  floor  to  the  window  sills,  which  formed  a  part 
of  the  wall  and  were  troweled  hard  while  setting.  These  low  walls  were  put 
in  after  the  structural  part  of  the  concrete  was  several  stories  above  them,  as 
shown  in  Fig.  60,  page  128. 

The  building  is  without  partitions  except  around  the  elevator  and  stair 
wells.  These  were  built  after  the  floors  were  completed,  and  instead  of  being 
located  directly  under  the  beams  or  ribs  they  were  placed  alongside  of  them, 
slots  being  left  in  the  floor  slab  so  that  they  could  be  poured  from  the  floor 
above  directly  into  the  forms  built  for  them.  The  reinforcement  of  these 
partition  walls  consists  of  %-inch  round  rods  15  inches  apart  both  horizontally 
and  vertically. 

The  exterior  columns  are  divided  into  blocks  by  horizontal  moldings  at- 
tached to  the  inside  of  the  form.  After  completing  the  building,  the  walls 
were  given  a  wash  of  Lafarge  cement. 

CONSTRUCTION. 

Two  mixing  plants  were  located  in  the  basement  of  the  building  near  the 
two  elevator  shafts.  The  arrangement  of  the  entire  plant  was  according  to 
the  Ransome  design.  Each  mixer  was  located  on  a  platform  about  3  feet 
above  the  floor  level,  and  the  raw  material  supplied  to  it  by  wheelbarrows. 
An  electric  motor  supplied  the  power.  The  hoist,  driven  by  a  separate  motor, 

125 


126 


received  the  concrete  directly  from  the  mixer,  and  raising  it  to  the  floor  where 
the  concrete  was  being  laid,  dumped  it  into  a  hopper,  from  which  it  was  fed 
by  a  gate  into  2-wheel  carts  and  conveyed  to  place.  Each  construction  plant 
cost  in  the  neighborhood  of  $2,500. 

The  building  was  completed  in  seventy-four  working  days,  the  average 
progress  being  10.4  days  per  story.  During  this  time  16,000  cubic  yards  of 
concrete  were  placed  and  950  tons  of  steel.  The  usual  gang  consisted  of  80 
carpenters  and  180  laborers. 

Fig.  60  illustrates  the  work  in  progress  on  the  fifth  floor,  where  the 
column  and  girder  forms  are  also  being  set  for  the  floor  above.  The  forms 
and  braces  are  removed  from  the  first,  second  and  third  floors,  and  they  are 
being  raised  from  the  fourth  floor  to  the  floor  above  by  falls  carried  by  a  tri- 
angular frame,  which  is  seen  projecting  above  the  work.  The  photograph 


Fig.  61. — View  Illustrating  Form  Construction  for  Bush  Terminal  Factory.  (See  p. 


also  shows  the  bracing  and  alignment  of  the  faces  of  the  exterior  column 
forms.  On  the  second  floor  the  panels  below  the  windows  are  being  poured, 
a  part  of  the  forms  being  still  in  place.  From  the  panel  next  to  the  corner 
and  also  from  the  panels  of  the  first  story  the  forms  have  been  removed  and 
show  the  finished  surface.  The  molding  of  the  columns  also  distinctly  ap- 
pears. 

The  photograph,  Fig.  61,  shows  the  general  layout  of  the  forms,  the 
girder  forms  extending  lengthwise  of  the  view  with  the  ribs  at  right  angles 
to  them.  The  rib  forms,  which  are  approximately  triangular,  rest  directly 
upon  the  sides  of  the  girder  molds,  and  narrow  pieces  of  plank  are  dropped 
between  them  to  form  the  bottom  of  the  rib. 

127 


128 


The  total  cost  of  the  building  complete  was  approximately  $450,000.  It 
has  automatic  sprinklers,  steam  heat,  ample  toilet  rooms,  heavy  freight  ele- 
vators, wire  glass  windows  in  metal  frames,  standard  automatic  fire  doors, 
hard  wood  floors,  and  so  forth,  to  make  really  a  model  factory. 


129 


130 


CHAPTER  X. 


PACKARD  MOTOR  CAR  FACTORY. 

The  Packard  Motor  Car  Company  at  Detroit,  Michigan,  turned  out  in 
1905  700  automobiles.  The  demand  for  these  cars  necessitated  an  enlarge- 
ment of  the  plant,  and  in  the  spring  of  1906,  after  careful  consideration  of  the 
various  types  of  construction,  it  was  decided  to  build  the  new  factory  of  re- 
inforced concrete.  The  building  illustrated  on  the  opposite  page  is  the  result. 

Plans  were  drawn  at  once  by  Mr.  Albert  Kahn,  architect,  and  the  con- 
tract was  let  to  the  Concrete  Steel  and  Tile  Construction  Company,  of  De- 
troit, the  Trussed  Concrete  Steel  Company  acting  as  engineers. 

The  structure,  as  is  shown  on  the  plans,  is  long  and  narrow,  and  in  the 
form  of  an  L,  so  that  all  parts  of  the  floor  are  well  lighted.  It  is  proposed 
at  some  future  time  to  extend  the  building  by  carrying  out  another  wing. 
At  present  there  are  two  stories,  and  the  roof  is  designed  as  a  floor  with  a 
temporary  covering,  as  described  below,  so  that  another  story  can  be  added 
at  a  later  date.  The  first  floor  is  laid  upon  the  ground  with  no  basement. 

The  building  is  designed  to  provide  very  large  floor  area  without  inter- 
ference of  columns.  A  single  row  of  columns  runs  through  the  center  of  the 
factory,  and  these  are  32  feet  apart  on  centers,  a  distance  slightly  greater 
than  the  space  between  the  line  of  columns  and  the  walls  on  each  side. 

Although  a  motor  car  appears  to  be  a  heavy  machine  in  itself,  the  parts 
are  comparatively  light,  and  by  placing  the  heavier  machinery  on  the  ground 
floor,  it  was  possible  to  allow  a  floor  load  of  only  100  pounds  per  square  foot, 
in  addition  to  the  dead  load  or  weight  of  the  structure  itself.  In  certain  parts 
of  the  floor,  this  load  is  increased,  around  the  elevators  especial  care  being 
taken  to  give  an  excess  of  strength.  This  comparatively  light  live  load  to- 
gether with  the  type  of  floor  construction  selected,  a  combination  of  tile  and 
concrete,  permitted  the  rather  unusually  long  spans. 

The  general  plan,  Fig.  63,  shows  the  layout  of  the  floor,  with  an  outline 
of  the  location  of  the  beams,  girders  and  columns. 

Fig.  64  presents  elevations  and  sections  taken  lengthwise  of  the  building, 
and  also,  at  the  right,  a  typical  or  transverse  section. 

FLOOR  SYSTEM. 

The  first  floor  is  built  directly  upon  the  ground.  The  top  soil  was  re- 
moved and  the  surface  thoroughly  tamped,  then  covered  with  6  inches  of 
cinders  rammed  hard  to  receive  the  concrete.  On  top  of  this  porous  layer,  a 


132 


133 


5-inch  thickness  of  concrete  in  proportions  i  part  cement  to  2  parts  sand  to 
5  parts  broken  limestone  was  spread,  and  covered  with  a  i-inch  mortar  sur- 
face, laid  before  the  concrete  below  had  set,  in  proportions  2  parts  cement  to 
3  parts  sand,  and  thoroughly  troweled  with  a  steel  trowel  to  a  smooth  surface. 
This  was  divided  into  sections  as  it  was  being  laid  to  provide  contraction 
joints. 

In  the  floor  above,  the  wide  spacing  of  the  columns,  already  mentioned, 
necessitated  beams  and  girders  of  unusual  length,  and  consequently  of  un- 
usual width  and  depth.  The  girders  (see  Fig.  63)  are  30  feet  8  inches  in  net 
length  between  columns,  or  32  feet  8  inches  on  centers,  and  measure  22  inches 
wide  by  36  inches  deep  from  top  of  slab.  Each  girder  supports  one  beam 
at  the  center  of  its  span,  the  alternate  beams  running  directly  into  the  col- 
umns. The  reinforcement,  which  consists  of  Kahn  trussed  bars*,  is  very 
clearly  seen  in  section  NN  in  the  figure.  The  girder  selected,  as  shown  on 
the  plan  below  it,  is  taken  at  the  intersection  of  the  two  wings  of  the  building, 
and  the  column  at  the  right  is  therefore  narrower  than  the  left-hand  support, 
the  latter  illustrating  the  typical  columns  in  the  building. 

The  floor  system,  as  already  mentioned,  is  designed  for  a  load  of  100 
pounds  per  square  foot  in  addition  to  the  weight  of  the  concrete  and  steel. 
The  design  is  figured  so  that  this  loading  will  not  produce  a  tension  in  the 
steel  exceeding  16,000  pounds  per  square  inch,  and  will  keep  the  compression 
in  the  concrete  everywhere  within  the  limit  of  500  pounds  per  square  inch.f 
The  proportions  of  the  concrete  are  one  part  Atlas  Portland  cement,  2  parts 
sand,  4  parts  broken  limestone,  the  exact  measurements  being  one  barrel  (4 
bags)  cement  to  7.56  cubic  feet  sand  to  15.10  cubic  feet  stone. 

The  shear  or  diagonal  tension  is  provided  for  by  bending  some  of  the 
tension  rods  and  also  by  the  bent-up  portion  of  the  individual  bars. 

The  beams,  of  which  a  typical  section,  MM,  is  also  shown  in  Fig.  63,  are 
27  feet  i  inch  net  span  between  girder  and  wall  column.  The  general  con- 
struction is  similar  to  the  girder  shown  above  it  and  labeled  beam  "B"  except 
that  fewer  bars  are  bent  up  because  the  shear  is  less.  The  section  of  the 
typical  beams  is  30  inches  deep  and  18  inches  in  width. 

A  somewhat  peculiar  slab  section  is  shown  in  the  upper  portion  of  section 
MM.  This  is  made  up  of  sections  of  tile  and  concrete  placed  alternately. 
The  floor  slab  is  14  feet  6  inches  net  span  between  beams,  and  consists  es- 
sentially of  a  series  of  concrete  beams  8  inches  deep  by  4  inches  in  width 
spaced  16  inches  apart  on  centers  and  reinforced  with  Kahn  trussed  bars. 
These  little  beams  run  directly  into  the  upper  surface  of  the  regular  beams, 
labeled  "A"  on  the  plan,  and  are  supported  by  them. 

Between  these  little  beams  hollow  tile  is  laid,  the  method  of  construction 
being  to  first  place  the  tile  upon  the  level  panel  form,  then  set  the  reinforcing 
metaHn  position  between  the  rows  of  tile,  and  pour  the  concrete.  The  ob- 

*    See  Illustration,  Fig.    107,   page   183. 

t  Figured  by  the  parabolic   formula,   or  nearly   600   pounds  by  the  straight-line   formula. 

134 


ject  of  the  insertion  of  tile  is  to  lighten  the  floor  slab,  and  thus  reduce  the 
weight  upon  the  beams  and  girders  by  occupying  space  which  must  other- 
wise be  solid  concrete.  It  also  permits  very  simple  form  construction,  con- 
sisting chiefly  of  a  large  plain  surface  readily  built  and  removed. 

After  hardening,  the  under  surfaces  of  the  floors  are  plastered  with  2 
inches  of  Portland  cement  mortar  to  hide  the  tile  and  form  the  ceiling.  On 
top  of  the  floor  slab,  a  2-inch  wearing  surface  of  cement  mortar  finish  is  also 
laid  to  make  the  finished  floor. 


Fig.  65. — Typical  Interior  Columns  in  Packard  Factory.    (See  p.  136.} 


The  beams  around  the  elevators  are  especially  constructed  to  sustain  a 
weight  of  8,000  pounds  live  or  superimposed  load,  plus  8,000  pounds  from  the 
counterweights,  plus  4,000  pounds,  the  weight  of  the  elevators  loaded. 

The  original  specifications  called  for  a  roofing  designed  to  carry  40  pounds 
per  square  foot,  but  it  was  afterwards  decided  to  build  this  as  a  floor  of  the 
same  construction  as  the  second  floor,  so  that  another  story  could  be  added 
when  required.  On  top  of  the  level  surface  thus  formed,  a  layer  of  cinders 

135 


was  spread  and  shaped  so  as  to  pitch  to  sumps;  a  i-inch  layer  of  mortar  was 
laid  on  the  cinders,  and  upon  this  tar  and  gravel  roofing. 

COLUMNS. 

The  interior  columns  are  in  general  24  inches  square  and  designed  for  a 
safe  loading  which  produces  a  compressive  stress  in  them  not  exceeding  450 
pounds  per  square  inch.  The  concrete  was  made  in  proportions  one  part 
Portland  cement  to  i^  parts  sand  to  2  parts  stone,  and  reinforced  with  Kahn 
trussed  bars,  as  indicated  in  Fig.  65  (p.  135). 

The  wall  columns  are  similar  in  design,  but  smaller  in  section  and  spaced 
1 6  feet  4  inches  apart  on  centers,  so  that  all  the  cross  beams  run  directly  into 
them.  A  longitudinal  beam  at  each  floor  line  connects  these  wall  columns 
and  also  supports  the  brickwork,  which  is  built  up  to  the  level  of  the  window 
sills. 


Fig.    66.— Stair    Details. 


bfl 
£ 


137 


STAIRS. 

The  stair  details  may  be  seen  in  Fig.  66  (p.  136).  They  consist  in  general 
of  a  slab  reinforced  with  Kahn  trussed  bars  and  surface,  with  a  i-inch  tread 
of  cement  mortar. 

A  photograph  of  the  stairs,  Fig.  67  (p.  137),  taken  soon  after  the  concrete 
was  laid,  very  clearly  illustrates  their  arrangement  and  design. 

CONSTRUCTION. 

The  factory  was  sixteen  weeks  in  building,  and  in  its  construction  2,100 
cubic  yards  of  concrete  were  laid  and  225  tons  of  steel  placed. 

The  arrangement  of  the  plant  is  clearly  shown  in  Fig.  68.     Two  mixing 


Fig.  68. — Plan  of  Construction  Plant.    (See  p.  138.} 

plants  were  located  as  shown,  one  with  a  Ransome  mixer  fed  by  an  automatic 
hoist,  and  one  with  a  Smith  mixer.  Each  of  the  mixers  dumped  into  a  bucket 
hoist,  which  elevated  the  concrete  to  a  bin  on  the  fourth  floor,  where  it  was 
placed  by  wheelbarrows.  The  work  of  construction  is  shown  in  the  photo- 
graph in  Fig.  69.  One  of  the  concrete  hoists  is  seen  on  the  left,  and  one  of  the 
double  platform  hoists  which  elevate  the  tile  and  steel  is  on  the  right.  The 
upper  surface  of  the  floor  slabs,  with  the  alternating  concrete  and  tile,  and  the 
top  surface  of  the  girders  and  beams  are  also  distinctly  visible  in  the  fore- 
ground. The  underside  of  the  floor,  with  the  alternate  tile  and  concrete  sur- 
face, is  illustrated  in  Fig.  70,  and  the  interior  of  the  finished  buildings  is  pre- 
sented in  Fig.  74  (p.  145). 

FORMS. 

For  the  forms,  i^-inch  lumber  was  used,  except  that  for  the  floor  panels 
No.  i  Norway  pine,  dressed  four  sides,  was  employed.  The  cost  of  lumber 
averaged  $27  per  thousand,  but  there  was  a  large  salvage,  that  is,  a  large  pro- 

138 


140 


141 


portion  of  the  lumber  was  suitable  for  use  on  another  job,  because  of  the 
wide  floor  slabs  and  large  beams  and  girders,  which  cut  up  the  stock  less  than 
usual. 

Typical  form  details  are  drawn  in  Fig.  71  (p.  141).  The  clamps  or 
brackets  of  the  column  forms  are  driven  up  with  wedges  so  as  to  make  tight 
and  prevent  twisting.  The  beam  molds  on  the  right  of  the  diagram  are  held 
together  with  iron  clamps  or  braces  placed  against  2  by  4  inch  battens,  which 
also  serve  as  supports  for  the  joists  which  carry  the  sheathing. 

The  centering  was  erected  so  that  the  column  forms  could  be  removed 
first,  then  the  sides  of  the  beam  molds,  and  next  the  floor  forms,  leaving  the 
bottom  of  the  beam  molds  with  the  shores  in  place.  These  shores  were  gen- 
erally left  in  three  or  four  weeks,  while  the  remainder  of  the  forms  were  taken 
down  in  two  or  three  weeks.  Owing  to  the  length  of  the  span  and  the  heavy 
weight  of  the  beam  molds,  the  bottoms  of  these  were  built  on  the  ground  and 
then  raised  to  place,  and  the  sides  were  constructed  in  position.  This  avoided 
the  elevating  of  the  completed  mold. 

Fig.  72  shows  the  exterior  of  the  building  under  construction,  with  the 
column  and  beam  forms  and  the  struts  still  in  place  in  the  second  story. 
Some  of  the  first  floor  shores  also  remain  to  support  the  principal  beams  and 
girders.  The  illustration  also  shows  the  platform  hoist  for  raising  the  tile. 

The  photograph  in  Fig.  73  was  taken  a  little  later,  and  shows  the  struc- 
tural portion  of  the  building  practically  completed  but  with  some  of  the  shores 
and  part  of  the  centering  still  in  place  on  the  upper  floor.  The  window  frames 
are  set  along  one  side  of  the  first  story  and  the  brickwork  laid  there.  In  the 
background  can  be  seen  the  stair  and  elevator  well  and  just  in  front  of  it  the 
concrete  hoist. 

The  exterior  view  of  the  completed  factory  is  shown  in  the  photograph, 
Fig.  62,  page  130. 


142 


bfl 


bfl 

.s 

o 

J3 

?/a 

c 
o 


bfl 


143 


a 

o 
o 


bJD 


144 


13 

I 

"3, 


145 


.5? 


146 


CHAPTER  XI. 


TEXTILE  MACHINE  WORKS. 

An  unusual  type  of  factory  building  was  erected  at  Reading,  Penn.,  by 
the  Textile  Machine  Works  during  the  winter  of  1904-5  for  the  manufacture 
of  machinery  for  cotton  and  woolen  mills.  Comparatively  light,  but  high 
speed,  machine  tools  were  installed,  such  as  lathes,  planers  and  drills. 

The  feature  of  most  interest  in  the  design  is  the  floor  system.  The 
columns  were  built  in  place  in  the  usual  way  by  pouring  concrete  into  wooden 
molds,  but,  instead  of  building  wooden  forms  in  place  for  the  floor  system  and 
pouring  the  concrete  into  them,  all  the  members  were  molded  separately  and 
placed  after  hardening.  The  design  of  the  beams  and  girders  also  was  de- 
cidedly unusual,  for  to  reduce  their  weight  and  the  quantity  of  concrete  in 
them,  the  Visintini  system  was  adopted,  in  which  the  members  are  of  open 
or  lattice  work,  formed  as  actual  trusses. 

The  Visintini  system  was  invented  by  Franz  Visintini,  an  architect  of 
Zurich,  Switzerland.  Although  applied  in  a  number  of  cases  in  Europe,  this 
building  was  its  first  introduction  into  the  United  States. 

The  Concrete-Steel  Engineering  Company,  of  New  York,  who  controls 
the  American  patents,  designed  the  building  and  also  acted  as  consulting  en- 
gineers during  erection.  Day  labor  was  employed  in  the  Construction,  the 
men  being  directly  upon  the  pay  roll  of  the  Textile  Machine  Works. 

The  building,  which  is  shown  complete  in  Fig.  75,  is  50  feet  wide  by  200 
feet  long  and  four  stories  high.  Wall  columns  are  spaced  12^2  feet  apart, 
and  a  center  line  of  columns  on  the  same  spacing  extends  through  the  center 
of  the  building.  The  principal  girders,  24  feet  long,  run  across  the  building, 
connecting  the  wall  and  center  columns. 


COLUMNS. 

The  column  footings  are  not  reinforced  but  are  stepped  as  shown  in  Fig. 
76,  and  laid  in  proportions  1 13 :6.  To  assist  in  transmitting  the  pressure  of 
the  columns,  which  are  of  richer  proportions,  1 12 14,  and  also  to  afford  a  bear- 
ing for  the  column  rods,  a  ^-inch  plate  was  set  3  inches  below  the  top  of  the 
footing.  After  laying  the  footings,  the  column  reinforcement  was  placed  with 
the  longitudinal  rods  butting  directly  upon  the  plate,  as  shown,  and  forms  of 

147 


a/tf  L-3  to  L-/&  Jhc/vs/re 
Fig.  76.— Details  of  Columns  in  Textile  Machine  Shop  (See  Fig.  78).    (See  p.  147.) 

148 


bfl 

£ 


149 


I 


ra 


IK 


dressed  white  pine  were  built  around  them.  The  concrete  of  the  column  was 
then  poured  in  the  usual  manner.  The  details  of  a  typical  interior  and  exter- 
ior column  are  shown  in  Fig.  76,  and  in  Fig.  77  (p.  149)  the  columns  are  il- 
lustrated as  they  appeared  with  the  shoulders  for  receiving  the  girders  and 
with  the  rods  projecting  upwards  so  as  to  join  on  the  columns  in  the  next 
story  above.  The  center  columns  in  the  lower  story  are  18x18  inches  square 
and  15x15  inches  for  those  above.  Wall  columns  are  15x15  inches  on  the  first 
floor  and  12x15  inches  above.  The  principal  reinforcement  in  the  columns 
through  the  middle  of  the  building  consists  of  four  1^4 -inch  vertical  rods  in 
the  two  lower  stories,  and  four  i-inch  rods  in  the  third  and  fourth  stories. 
Three  half-inch  Thacher  rods*  are  also  inserted  in  the  exterior  columns.  Oc- 
casional loops  of  small  rods  hold  the  heavier  rods  in  place,  and  assist  in  re- 
sisting shear.  The  ends  of  the  principal  rods  are  planed  smooth  and  they  are 
butted  and  connected  with  a  6-inch  length  of  pipe  sleeve,  so  that  perfect  com- 
pression is  assured.  The  outside  rows  of  columns  are  similar  except  that  the 
rods  are  differently  spaced.  The  pressure  on  the  concrete  is  limited  to  350 
pounds  per  square  inch. 


FLOOR  SYSTEM. 

Foundation,  floor  and  roof  plans,  and  sketches  of  column  footings  are 
drawn  in  Fig.  78. 

Running  across  the  building  from  column  to  column  and  12^  feet  apart 
on  centers  are  the  large  Visintini  lattice  girders  24  feet  long. 

In  ordinary  design  these  would  be  connected  by  floor  beams  spaced  6  or 
8  feet  apart,  with  slabs  between  the  beams.  The  Visintini  system,  however, 
permits  the  slabs  and  floor  beams  to  be  laid  as  one ;  that  is,  after  placing  the 
girders  the  floor  beams  were  laid  from  girder  to  girder  but  close  together  so 
as  to  form  a  floor  slab  themselves.  For  a  wearing  surface,  a  maple  floor  was 
laid  upon  2  by  4-inch  stringers,  which  were  bolted  together  at  the  ends  so  as 
to  tie  the  floor  together  lengthwise  of  the  building  as  well  as  to  form  nailing 
strips.  Cinder  concrete  was  placed  between  the  strips. 

The  details  of  a  typical  floor  girder,  roof  girder  and  floor  beam  are  shown 
in  Fig.  79.  The  girders  are  shaped  like  a  Pratt  truss,  a  common  type  used 
in  steel  bridges,  and  the  computations  of  stresses  were  made  as  in  bridge 
design.  The  bottom  chord  consists  of  a  slab  of  concrete  reinforced  with  3 
round  rods  to  take  all  of  the  tension,  and  the  top  chord  in  compression,  is 
similarly  reinforced.  The  vertical  web  members,  which  are  in  compression, 
are  of  plain  concrete,  while  the  diagonals  are  each  reinforced  for  tension  with 
rods,  whose  ends  are  attached  to  the  rods  of  the  top  and  bottom  chords. 

The  floor  beams  are  only  6  inches  thick  and  12  feet  5  inches  long,  and 
these,  as  stated  above,  also  form  the  slab,  being  placed  close  together.  They  are 

*   See  illustration,  Fig.    102,  page   179. 


- 


A 


M 


W) 


152 


W) 


153 


§• 

.£ 
C/> 

I 

^ 
u 

03 


00 

bi) 

£ 


designed  and  computed  like  a  Warren  truss  with  all  of  the  web  members  in- 
clined at  45°,  half  of  them  in  tension  and  half  in  compression. 

One  of  the  chief  advantages  of  this  type  of  construction  already  noted, 
is  in  the  method  of  molding  the  beams  and  girders  so  as  to  reduce  the  cost 
of  forms.  In  this  case  the  work  was  greatly  facilitated  because  the  building 
was  erected  in  winter.  The  beams,  of  which  there  are  about  2,900,  were 
molded  on  the  ground  in  an  adjacent  building,  as  shown  in  Fig.  80  (p.  153). 
At  the  left  of  the  photograph  is  the  bottom  board  of  the  forms,  to  which  are 
screwed  triangular  cast  iron  plates.  These  locate  the  triangular  cores  which 
were  set  upon  them.  Two  boards  formed  the  sides  of  the  mold,  and  when 
these  were  set  and  clamped,  the  reinforcement  previously  bent  to  shape  and 
formed  into  three  trusses,  was  carefully  placed.  The  soft  concrete  was  then 
poured  in  and  lightly  tamped.  The  proportions  for  the  beam  concrete,  based 
on  cement  loosely  measured,  were  one  part  Portland  cement  to  one  part  sand 
to  three  parts  stone  screenings.  The  floor  beams  weigh  only  480  pounds  each. 

The  cores,  which  were  oiled  before  placing,  were  pulled  a  few  hours  after 
pouring,  and  the  side  and  bottom  forms  were  left  on  for  two  days,  when  the 
beams  were  hard  enough  to  move.  After  setting  about  10  to  30  days  longer, 
as  needed,  they  were  carried  to  the  building  and  raised  to  place.  They  were 
run  on  to  the  first  floor  of  the  building,  and  then  raised  through  an  open  bay 
to  the  floor  where  they  were  required  by  a  platform  elevator.  A  view  of  the 
girders  in  place  and  of  a  floor  beam  on  the  elevator  is  shown  in  Fig.  81. 

Two  of  the  floor  beams  were  tested  to  destruction  and  broke  under  a  load 
of  pig  iron  weighing  342  pounds  per  square  foot.  The  building  is  designed 
for  a  safe  working  load  of  75  pounds  per  square  foot. 

The  girders  weigh  about  three  tons  each,  and  were  molded  upon  the  floor 
immediately  underneath  their  final  position,  so  that  they  required  only  to  be 
hoisted  into  place,  a  distance  of  14  feet,  which  was  done  by  means  of  a  special 
derrick  and  two  strong  hoists. 

The  proportions  were  one  part  Portland  cement  (measured  loosely),  il/2 
parts  sand,  and  3^  parts  broken  trap  rock  passing  a  i^-inch  ring. 

To  tie  the  columns  together  across  the  building,  the  floor  beams  were 
placed  with  a  5-inch  opening  between  their  ends,  and  this  space  filled  with 
concrete  in  which  was  imbedded  a  rod,  as  shown  just  above  the  cross-section 
of  the  girder  in  the  lower  portion  of  Fig.  79.  The  method  of  placing  the  floor 
beams  is  illustrated  in  Fig.  77.  They  are  laid  on  top  of  the  girders  and  are 
so  thin  that  they  appear  in  the  photograph  like  planks,  but  careful  inspection 
of  the  beams  at  the  right  of  the  photograph,  which  have  just  been  placed, 
will  show  their  lattice  formation. 

Another  view  of  the  building  under  construction  is  shown  in  Fig.  82 

(P-  157)- 

155 


COST. 

The  total  cost  of  the  building  was  about  $40,000,  divided  as  follows 

Concrete  materials  $5,961.66 

Iron   and    steel 6,277.46 

93,000  feet   B.   M.  lumber 2,514.61 

Excavating    388.23 

Foundry  work  (casting  for  cores) 642.20 

Machine  shop  work  (making  all  forms) 3,295.21 

Carpenter    work 4,971.83 

Labor  molding  and  pouring  concrete 7,919.27 

Labor  placing  concrete  beams 586.35 

Labor  (outside  of  concrete  work  proper) 2,422.25 

Brick  walls,  wooden  floors  and  trim 4,000.00 


Total    $38,979.07 

This  sum  does  not  include  the  cost  of  engineering  nor  of  general  expense. 

About  178  tons  of  steel  were  used  in  the  reinforcing  and  the  cost  of 
bending  and  placing  it  was  about  y2  cent  per  pound;  3,590  barrels  of  Atlas 
Portland  cement  were  used,  1,400  tons  of  stone  and  1,495  tons  of  sand. 

The  total  cost  of  the  completed  building  including  the  finish  was  7.7  cents 
per  cubic  foot. 


156 


157 


CHAPTER  XII. 


FORBES  COLD  STORAGE  WAREHOUSE. 

Reinforced  concrete  is  admirably  adapted  to  the  construction  of  cold 
storage  warehouses  because  of  the  advantages  from  a  sanitary  standpoint.  A 
monolithic  floor  construction,  free  from  structural  joints  and  seams,  fireproof, 
waterproof,  and  practically  vermin  proof,  is  unquestionably  an  ideal  floor  con- 
struction for  this  type  of  building.  These  advantages,  together  with  the  small 
cost  of  maintenance  and  favorable  insurance  rates,  led  to  its  selection  by  Mr. 
W.  S.  Forbes  as  the  structural  material  for  the  cold  storage  warehouse  and 
abattoir  at  Richmond,  Va. 

The  bids  for  the  construction  indicated  that  it  would  cost  about  10  per 
cent,  more  to  build  of  reinforced  concrete  with  brick  walls  than  to  carry  out 
the  design  in  wood,  but  the  owner  was  convinced  that  the  more  serviceable 
and  satisfactory  results  attained  with  the  concrete  outweighed  the  slight  in- 
crease in  cost.  As  a  result,  this  building  is  one  of  the  most  thoroughly  equip- 
ped cold  storage  plants  and  slaughter  houses  in  the  country. 

The  plant  was  erected  by  Mr.  Walter  P.  Veitch,  general  contractor,  from 
plans  of  Messrs.  Wilder  and  Davis,  of  Chicago,  packing  house  experts.  The 
reinforced  concrete  work  and  structural  features  of  the  building  were  de- 
signed by  the  General  Fireproofing  Company,  of  Youngstown,  O.,  who  sup- 
plied the  steel  reinforcement  for  the  building  and  superintended  its  installa- 
tion. The  structure  is  160  feet  7  inches  long,  85  feet  g}4  inches  wide  at  one 
end,  diminishing  to  a  width  of  79  feet  at  the  other  end.  A  part  of  the  build- 
ing is  six  stories  high  with  a  basement  in  addition,  the  remaining  portion 
having  four  stories  and  basement. 

The  two  lower  stories  are  utilized  for  cold  storage  purposes,  and  are  in- 
sulated from  the  outside  and  from  the  floors  above  by  10  inches  of  cork  in- 
sulation on  top  of  the  concrete  floor. 

The  two  lower  floors  are  finished  with  i-inch  granolithic.  This  enables 
the  floors  to  be  kept  clean  and  sanitary  by  flushing  with  the  hose  and  srub- 
bing,  gutters  leading  to  drains  being  provided  to  collect  the  drip  or  scraps, 
and  the  refuse  from  the  meats  and  their  by-products. 

The  third  story  is  the  shipping  floor,  and  its  ceiling  is  completely  equip- 
ped with  a  system  of  trolleys  hanging  from  especially  designed  hangers  sus- 
pended from  the  concrete  beams. 

The  fourth  floor  is  used  as  an  office  and  general  salesroom,  and  this  floor 
is  so  insulated  from  above  and  below  as  to  maintain  a  uniform  temperature. 

158 


A  portion  of  the  fifth  floor  is  devoted  to  ice  storage,  and  the  remainder 
is  occupied  by  the  hanging  room,  hog  cooler  department,  and  brine  chambers. 
Above  this  floor,  under  the  roof,  is  a  thoroughly  insulated  air  space. 

The  meats  and  other  products  are  transferred  from  one  story  to  another 
by  means  of  large  elevators  in  shafts  whose  walls  are  insulated  with  cork. 

The  live  loads  on  the  different  floors  vary  from  250  to  400  pounds  per 
square  foot,  the  heavier  loads  occurring  mostly  on  the  fifth,  where  salt  and 
general  merchandise  tubs  of  lard  and  barrels  of  pork  are  stored  for  sale. 

DETAILS  OF  CONSTRUCTION. 

The  general  plan  of  the  warehouse  is  shown  in  Fig.  83  (p.  159),  the  cross 
section  in  Fig.  84,  the  longitudinal  section  in  Fig.  85,  and  the  south  elevation 
in  Fig.  86. 

The  first  and  second  stories,  that  is,  the  basement  and  sub-basement,  are 
below  grade,  and  surrounded  by  heavy  concrete  foundation  retaining  walls. 


Fig.  84. — Cross-Section  of  Forbes  Cold  Storage  Warehouse. 

From  the  street  grade  the  exterior  walls  are  brick,  varying  in  thickness  from 
20  inches  above  the  foundation  to  13  inches  at  the  top.  Bearing  walls,  al- 
though more  expensive,  were  selected  in  preference  to  skeleton  construction 
with  curtain  walls  to  provide  more  complete  insulation. 

The  interior  columns  are  of  concrete,  reinforced  with  four  vertical  rods, 
varying  from  i  inch  to  y\  inch  in  the  different  stories,  and  tied  at  intervals  of 

1 60 


I 

4-> 

•a 

c 
o 


W> 

£ 


ffl 


161 


i63 


1 64 


about  12  inches  with  wire  ties.  The  columns  are  located  16  feet  apart  in  one 
direction  and  20  feet  apart  in  the  other. 

The  girders  run  across  the  building  on  the  1 6-foot  span,  with  beams  at 
right  angles  to  them  spanning  from  column  to  column,  and  also  through  the 
central  points  of  the  girders,  thus  making  the  bays  20  feet  by  8  feet. 

The  beams  and  girders  are  of  the  same  depth  throughout  the  building, 
namely  24  inches,  with  a  view  to  facilitating  the  installation  and  operation 
of  the  trolley  systems.  The  floor  slabs  and  the  roof  slabs,  which  are  reinforced 
with  expanded  metal,  are  4^  inches  and  $y2  inches  respectively. 

An  interior  view  of  one  of  the  floors  after  completing  the  concreting  is 
given  in  Fig.  87  (p.  163). 

GIRDER  FRAMES. 

The  details  of  the  reinforcement  in  the  beams  and  girders  are  shown  in 
Fig.  88  (p.  164),  with  the  typical  sizes  of  steel  for  a  floor  carrying  250  pounds 
per  square  foot  in  addition  to  the  weight  of  the  concrete. 


Fig.  89. — Placing  of  Pin-Connected  Girder  Frames.     (See  p.  167.) 

Each  frame  is  a  complete  truss  of  the  pin-connected  girder  system,  two 
or  more  frames  constituting  the  reinforcement  for  each  beam  and  girder.  At 
intersections  the  frames  are  connected  by  steel  links  and  bolts,  thus  provid- 
ing continuous  ties  across  the  building  in  both  directions. 

165 


DETAIL  OF  INTERSECTION  or  BCAM  &Gim£* 


Tl  r|    rp rlf^gfl 

httHpaE 


T 


|Hn      in      gn     Un 


m 


m 


THROUGH  GUUXM 

Fig.  90.— Details  of  Form  Construction.      (Sec  p.  167.) 


166 


The  frames  were  designed  for  the  special  floor  loads  and  fabricated  in  the 
shop  of  the  General  Fireproofing  Company  at  Youngstown,  Ohio,  then  shipped 
to  the  building  ready  for  installation  in  the  forms.  The  tension  and  shear 
members  are  held  rigidly  in  place  by  steel  collars  and  pneumatically  driven 
steel  wedges,  so  that  the  displacing  of  the  reinforcement  by  careless  work- 
manship is  impossible.  The  placing  of  the  reinforcement  is  illustrated  in 
Fig.  89  (p.  165). 

FORMS. 

Isometric  views  of  sections  of  the  forms  are  illustrated  in  Fig.  90.  The 
form  lumber  was  Virginia  pine,  planed  three  sides,  or  else  tongue-and-grooved, 
and  cost  $20  per  thousand.  The  form  construction  was  simplified  by  the  uni- 
form depth  of  the  beams  and  girders,  each  of  them  being  24  inches  deep, 
measured  from  top  of  the  slab.  The  forms  were  left  in  place  from  two  to  three 
weeks,  being  used  on  the  average  three  times. 

CONSTRUCTION  PLANT 

The  construction  plant  consisted  of  a  Smith  mixer  with  elevator  for 
hoisting  the  concrete  in  wheelbarrows,  from  which  it  was  dumped  into  place. 
The  plant  cost  approximately  $2,000,  and  was  operated  by  a  gang  of  about 
twenty  men,  in  addition  to  the  carpenters  and  steel  men. 

MATERIALS  AND  COST. 

The  bid  for  the  concrete  work  was  $27,000,  and  for  the  completed  struc- 
ture about  $64,000.  Some  2,050  cubic  yards  of  reinforced  concrete  were  laid 
in  the  building,  besides  1,900  cubic  yards  of  plain  concrete  in  the  foundations 
and  foundation  walls. 

Six  months  were  occupied  in  the  erection,  the  average  progress  above  the 
basement  being  about  fourteen  days  per  story.  The  quantity  of  steel  used 
was  115  tons,  and  its  cost  made  into  trusses  and  delivered  at  the  building  was 
approximately  3  cents  per  pound.  The  placing  was  said  to  cost  only  $1.50 
per  ton. 

The  concrete  was  mixed  in  proportions  of  one  part  Atlas  Portland 
cement,  two  parts  sand  and  four  parts  stone,  the  labor  of  mixing  and  placing, 
exclusive  of  the  forms  and  steel  work,  being  about  $1.50  per  cubic  yard. 


bi 


168 


CHAPTER  XIII. 


BLACKSMITH   AND   BOILER  SHOP  OF  THE  ATLAS  PORTLAND 

CEMENT  COMPANY. 

At  the  plant  of  the  Atlas  Portland  Cement  Company,  in  Northampton, 
Pa.,  concrete  is  used  extensively  in  construction,  not  only  in  foundations  and 
for  the  cement  storehouses,  but  also  for  the  floors  and  walls  of  the  newer 
buildings. 

In  1906  a  new  blacksmith  and  boiler  shop  was  built  with  a  10-ton  crane 
extending  from  wall  to  wall  and  running  upon  reinforced  concrete  arched 
beams.  The  building  was  designed  by  the  company's  engineer  and  built  by 
day  labor.  It  is  shown  complete  on  the  opposite  page. 

DESIGN. 

The  shop  is  309  feet  9  inches  long,  55  feet  6  inches  wide  and  31  feet  2 
inches  high  to  the  bottom  of  the  roof  trusses,  this  height  being  necessary  for 
the  traveling  of  the  crane. 

The  plan  of  the  shop  is  shown  in  Fig.  92,  and  the  elevations  and  sections 
in  Figs.  93,  94,  95. 

The  walls  consist  of  piers  14  feet  on  centers,  with  wall  panels  and  win- 
dows between  them.  These  piers  are  made  of  heavy  section  (see  Fig.  93)  to 
support  the  crane,  and  for  this  purpose  they  project  into  the  building  23 
inches  as  far  up  as  the  crane  runway,  and  at  the  top  are  connected  with  arches 
which  are  laid  at  the  same  time  and  form  a  part  of  the  wall.  The  arches  are 
reinforced  with  five  y^  -inch  rods  spaced  5  inches  apart.  The  crane  run  is 
shown  in  section  BB,  Fig.  93,  and  also  on  a  large  scale  in  the  detail  above  it. 
An  8-inch  by  lo-inch  yellow  pine  timber  is  bolted  directly  to  the  concrete 
beam,  and  upon  this  rests  the  track.  The  walls  between  the  piers,  which  are 
dovetailed  into  them,  as  shown,  are  9  inches  thick.  This  is  somewhat  ex- 
cessive, but  the  extra  quantity  of  concrete  may  be  justified  by  the  low  cost 
of  materials  and  the  lean  proportions  of  the  concrete,  which  are  i  part  cement 
to  4  parts  sand  to  5  parts  gravel.  There  is  no  reinforcement  in  the  wall  panels 
except  directly  above  the  windows. 

Fig.  95  (p.  173)  shows  a  cross-section  of  the  shop  with  its  steel  roof 
trusses  and  an  outline  of  the  crane. 

CONSTRUCTION 

Somewhat  unusual  methods  of  construction  were  employed.     The  piers 

169 


170 


i  i\ii  i»»tj — i    > — c/yny ^f 

~~lif~    ~~o~~' 


171 


172 


were  first  run  up  to  the  full  height  of  the  building,  as  illustrated  in  the  photo- 
graph, Fig.  96.*  Then  the  panel  forms  were  placed,  as  in  Fig.  97,  and  the 
concrete  poured  between  them. 

The  window  frames  had  been  set  in  advance,  so  that  the  openings  were 
formed  in  each  wall  panel  as  it  was  poured.  The  only  tie  rods  which  were 
inserted  to  connect  the  piers  and  the  wall  panels  were  at  the  corners  of  the 
building,  where  j^-inch  horizontal  rods  2^  feet  long  were  placed  every  3  feet 
in  height.  (See  Fig.  93.) 

Fig.  98  is  a  photograph  illustrating  the  side  walls  after  completion. 


Fig.  95.— Cross-Section  of  Blacksmith  and  Boiler  Shop  of  the  Atlas  Portland  Cement 

Company.     (See  p.  /6p.) 


Above  the  foundations  of  the  shop,  792  cubic  yards  of  concrete  were  re- 
quired, with  only  5,570  pounds  of  steel.  In  the  foundation  460  cubic  yards 
were  laid  in  addition.  The  concrete  was  mixed  by  hand,  and  the  usual  gang 
consisted  of  2  foremen,  17  men  mixing,  4  men  hoisting,  4  men  placing,  and  6 

*  This  photograph  and  the  two  which  follow  it  are  from  a  different  building  of  the  Atlas  plant,  but  the 
method  of  construction  is  the  same. 

173 


Fig.  96. — Wall  Piers  for  an  Atlas  Portland  Cement  Company  Building.    (See  p.  173.} 


Fig.  97.— Pane]  Wall  Forms  for  an  Atlas  Portland  Cement  Company 
Building.      (See  p.  173.} 

174 


bfl 

i 


I 
t 

o 
O 


I 


b 


carpenters.  The  wages  for  the  laborers  ranged  from  $1.20  to  $1.50  per  day, 
with  a  $2  rate  for  the  carpenters.  The  total  cost  of  the  concrete  in  the  founda- 
tions and  walls  was  $29,328,  which  is  equivalent  to  only  $4.93  per  cubic  yard 
of  concrete,  an  exceptionally  low  price.  The  cheapness  of  labor  partially  ac- 
counts for  the  low  cost.  Ordinarily,  in  building  construction  with  thinner 
walls  and  higher^  material  and  labor  costs,  the  unit  price  per  cubic  yard  will 
be  greatly  in  excess  of  this  figure. 

The  forms,  of  hemlock  lumber,  costing  $25  per  thousand,  were  dressed 
only  on  the  side  next  to  the  concrete.  About  19,000  feet  of  lumber  was  used 
at  a  cost  of  $485,  the  labor  on  forms  being  about  $5,500.  Although  the  forms 
were  used  ten  times,  the  Engineer  estimates  the  salvage  for  another  similar 
job  to  be  about  60  per  cent.,  as  the  lumber  was  but  slightly  injured. 

On  the  surface  of  the  ground  next  to  the  building,  a  concrete  gutter  is 
laid  to  carry  off  the  surface  water  and  the  roof  drainage.  A  detai]  section  is 
given  in  Fig.  99. 


Fig.  99. — Drainage  Gutter.     (See  p.  176.} 

COAL  TRESTLE. 

The  coal  trestle,  which  is  shown  in  the  photograph,  Fig.  100,  is  supported 
upon  bents  of  reinforced  concrete  13  feet  apart,  resting  upon  heavy  concrete 
foundations.  The  piers  of  each  bent  are  20  inches  square  and  capped  by  a 
reinforced  concrete  girder  with  an  arched  bottom  surface.  Supporting  the 
track  are  pairs  of  channel  irons  bolted  to  the  concrete  girders.  At  intervals 
in  the  trestle,  diagonal  tie  rods  with  turnbuckles  are  placed  in  two  adjacent 
bays,  the  rods  extending  from  the  top  of  one  bent  to  the  bottom  of  the  next, 
so  as  to  guard  against  danger  from  longitudinal  expansion  and  contraction  of 
the  stringers  as  well  as  any  longitudinal  thrust  due  to  the  movement  of  the 
trains. 


I   a 


177 


CHAPTER  XIV. 


DETAILS   OF  CONSTRUCTION. 

To  provide  better  adhesion  or  bond  between  the  steel  and  concrete  than 
is  given  by  round  or  square  rods,  many  types  of  deformed  bars  have  been  in- 
vented, and  those  most  commonly  used  in  the  United  States  are  illustrated 
in  the  pages  which  follow.  Views  are  also  shown  of  a  number  of  systems  of 
assembling  the  steel  or  arranging  the  reinforcement  for  application  to  special 
conditions. 

In  addition  to  this  digest  of  systems  of  reinforcement,  a  number  of  photo- 
graphs are  presented  of  details  of  construction  most  commonly  met  with  in 
reinforced  concrete  buildings.  In  this  connection  are  shown  photographs  of 
concrete  block  walls,  surface  finish  for  concrete  walls,  concrete  piles,  and 
concrete  tanks. 

SYSTEMS  OF  REINFORCEMENT. 

RANSOME  TWISTED  BARS.— One  of  the  oldest  types  of  reinforcing 
steel  is  the  square  twisted  bar  illustrated  in  Fig.  101,  invented  by  Mr.  E.  L. 
Ransome,  of  the  Ransome  &  Smith  Co.,  and  used  as  long  ago  as  1894. 


Fig.  101.— Ransome  Twisted  Bar.     (See  p.  161.) 

Twisted  bars  may  be  purchased  ready  to  use,  or  on  a  large  job  may  be 
twisted  on  the  work.  The  number  of  twists  per  linear  foot  depends  upon  the 
diameter;  thus,  for  ^4-inch  bars  there  may  be  five  twists  per  foot  and  for 
i -inch  bars  one  twist  per  foot. 

In  computing  cross-section  area  of  steel  in  reinforced  concrete,  the 
twisted  bars  are  figured  as  square  bars  of  the  dimension  before  twisting. 
Twisted  bars  are  employed  in  the  Pacific  Coast  Borax  Refinery  and  the  Bul- 
lock .Electric  Company  shop,  described  in  Chapters  IV  and  VII. 

178 


THACHER  BAR. — The  Thacher  bar,  Fig.  102,  was  designed  and  patent- 
ed by  Mr.  Edwin  Thacher,  of  the  Concrete  Steel  Engineering  Company. 
Round  bars  are  rerolled  to  the  shape  indicated.  Thacher  bars  are  used  in 
parts  of  the  Textile  building,  Chapter  XI. 


Fig.  102.— Thacher  Bulb  Bar.     (See  p.  179.} 

JOHNSON   CORRUGATED   BAR.— The  corrugated,  or  Johnson  bar, 
Fig.  103,  is  the  invention  of  Mr.  A.  L.  Johnson,  of  the  Expanded  Metal  and 


Fig.  103. — Johnson  or  Corrugated  Bar.     (See  p.  179.) 

Corrugated  Bar  Company.  It  is  a  form  of  square  bar  with  alternate  eleva- 
tions and  depressions  to  grip  the  concrete.  The  normal  size  and  net  sections 
are  given  in  the  following  table: 

Areas  and  Weights  of  Johnson  Bars  (New  Style). 
Nominal  diameter,  inches.        Area,  square  inches.     Weight  per  linear  foot. 


•74 


0.06 

O.II 
0.25 

0-39 
0.56 
0.77 
1. 00 

1.56 


0.24 

0.38 
0.85 

1.33 
1.91 

2.60 

3.40 
5.31 


The  Johnson  bar  is  used  in  the  Wholesale  Merchants'  Warehouse,  Nash- 
ville, Tenn.,  described  in  Chapter  VIII. 

UNIVERSAL  BAR. — A  type  of  bar  somewhat  similar  to  the  Johnson 
bar  is  shown  in  Fig.  104.  This  is  manufactured  by  the  Rogers  Shear  Com- 
pany and  the  sale  controlled  by  the  Expanded  Metal  and  Corrugated  Bar 
Company. 

DIAMOND  BAR.— The  Diamond  bar,  Fig.  105,  is  one  of  the  most  re- 
cent types  of  rolled  bar  and  the  invention  of  Mr.  William  Mueser,  of  the 
Concrete  Steel  Engineering  Company.  The  sizes  correspond  to  those  of 
square  bars  as  shown  in  the  following  table: 

179 


Areas  and  Weights  of  Diamond  Bars. 

Size  Y\  in.     %  in.     ^  in.     ^s  in.     -Vj  in.  7/s  in. 

Area  in  square  inches     .0625     .1406         .25         .39         .56  .76 

Weight  per  foot 213       .478           .85        1.33       1.91  2.60 


i  n.  i  i/J  in. 
i. oo  1.56 
340  5-31 


Fig.  104. — Universal  Bar.     (See  p.  179.} 


Fig.  105. — Diamond  Bar.     (See  p.  179.) 

COLD  TWISTED  LUG  BAR.— A  modification  of  the  twisted  bar  is 
the  twisted  lug  bar,  Fig.  106,  made  by  the  General  Fireproofing  Company. 
This  bar  is  used  in  the  columns  of  the  Forbes  Building,  described  in  Chapter 
XII. 


(Patented) 


Fig.   106.— Twisted  Lug  Bar.     (See  p.  180.} 


KAHN  TRUSSED  BAR.— The  Kahn  trussed  bar,  Fig.  107  (p.  183), 
invented  by  Mr.  Julius  Kahn,  of  the  Trussed  Concrete  Steel  Company,  is 
rolled  with  flanges,  which  are  bent  up,  as  shown  in  the  figure,  to  resist  the 
shear  in  the  beam.  The  Kahn  bar  is  employed  in  the  Packard  Building,  de- 
scribed in  Chapter  X. 

CUP  BAR. — The  cup  bar,  another  product  of  the  Trussed  Concrete  Steel 
Company,  is  rolled  with  four  longitudinal  ribs  connected  at  frequent  inter- 
vals by  cross  ribs  so  as  to  form  cup  depressions  between  them  designed  to 
grip  the  concrete. 

Areas  of  cross-section  of  cup  bars  are  made  to  correspond  to  square  bars 
of  the  same  nominal  size. 

1 80 


EXPANDED  METAL  MESHES. 


Designation 

Js  •£ 

t 

•d 

in 

«3j. 

gs 

a  »§ 

CS 

8  „ 

ft? 

S 

cs 

"S 
w 

'/I    O 

fl 

1  "S 

J3   -- 

£  9 

fit 

•g 

3 

1  = 

a  o 

""  o 

i  ^ 

•si 

fc  « 

n 

sP 

V 

s  — 

£  "0 

?3     U-i 

'x'     ^ 

E  2 

J3,2 

% 

V 

O    . 

.^f    ® 

N 

a 

S    ' 

B 

o  £ 

V    fe 

« 

s 

B 

l/2  in. 

No.  18 

Standard 

.209 

•74 

4  ft.  or  5  ft.  x  8  ft. 

5 

^i  in. 

"     13 

" 

.225 

.80 

6  ft.  x  8  ft.  or  12  ft. 

5 

24O 

T-l/2  in. 

"       12 

<  < 

.207 

.70 

4  ft.  x  8  ft.  or  12  ft. 

5 

160 

2      in. 

"       12 

" 

.166 

•56 

5  ft.  x  8  ft.  or  12  ft. 

5 

200 

3      in. 

"     16 

" 

.083 

.28 

6  ft.  x  8  ft.  or  12  ft. 

10 

480 

3      in. 

"       10 

Light 

.148 

•50 

6  ft.  x  8  ft.  or  12  ft. 

5 

240 

3      in. 

"       10 

Standard 

.178 

.60 

6  ft.  x  8  ft.  or  12  ft. 

5 

240 

3      in. 

"       10 

Heavy 

.267 

.90 

4  ft.  x  8  ft.  or  12  ft. 

5 

160 

3      in. 

"       10 

Extra  Heavy 

.356 

i.  20 

6  ft.  x  8  ft.  or  12  ft. 

3 

144 

3      in. 

"       6 

Standard 

.400 

1-38 

5  ft.  x  8  ft.  or  12  ft. 

3 

120 

3      in. 

"       6 

Heavy 

.600 

2.07 

5  ft.  x  8  ft.  or  12  ft. 

3 

120 

4      in. 

"     16 

Old  Style 

•093 

.42 

4^  ft.  x8  ft.  or  9  ft. 

6 

216 

6      in. 

14      4 

Standard 

.245 

.84 

5  ft.  x  8  ft.  or  12  ft. 

5 

200 

6      in. 

"      4 

Heavy 

.368 

1.26 

5  ft.  x  8  ft.  or  12  ft. 

3 

120 

LATHING. 


Designation 

Gage  U.  S. 
Standard 

Size  of 
Sheets 

Sheets  in  a 
Bundle 

Sq.  Yards 
in  a  Bundle 

Weight  Per 
Sq.  Yard 

A 

24 

18  x  96                9 

12 

4>^  Ibs. 

B 

27 

18  x  96 

9 

12 

3         " 

Special  B 

27 

20X   X  96 

9 

I3tf 

2^    " 

Diamond  No.  24 

24 

22l/£  X  96 

9 

15 

3       4< 

Diamond  No.  26 

26 

24  x  96 

9 

16 

2%    " 

181 


2 

Q 


S 


w 

N 


Q 

Z 


J ! 
&  i 

1  i 
s    % 

2  8 

m 


1 1 

3      ft 


II 

II 
ft 
?  J 

:  £S  S 


ps 

all 
:  £S 


sfgi 

CO 
S  8 


*^ 

OJ 

•s 

s 

<u 

T3 

T3 

•Ss 

c-S 

IH 
03 

1 

cd   G 

cd 

a  « 

•*-• 

x  a 

C/3 

W  E 

"o 

o 

|° 

n 

•4-> 
V 

cj 

^ 

182 


Fig.  107.— Kahn  Trussed  Bar.     (Sec  p.  180.} 

EXPANDED  METAL. — One  of  the  oldest  forms  of  sheet  reinforce- 
ment is  expanded  metal  invented  by  Mr.  John  T.  Golding. 

Sheet  steel  is  slit  in  a  special  machine  and  then  pulled  out  or  expanded 
so  as  to  form  a  diamond  mesh.  For  convenient  reference,  the  standard  sizes 
and  gages  as  adopted  by  the  Associated  Expanded  Metal  Companies  are 
shown  in  the  illustration,  Fig.  108  (p.  182),  and  are  tabulated  on  page  181. 

Expanded  metal  for  slab  reinforcement  is  employed  in  the  Lynn  storage 
warehouse,  Chapter  VI,  and  the  Forbes  cold  storage  warehouse,  Chapter  XII. 


Fig.  109.— Laying  Clinton  Welded  Wire  in  Decauville  Garage,  New  York.     (See  p.  183.} 

CLINTON  WELDED  WIRE.— Clinton  welded  wire  fabric,  made  by  the 
Clinton  Wire  Cloth  Company,  is  manufactured  in  different  sizes  of  mesh  and 
different  gages  of  wire.  As  commonly  made,  the  longitudinal  strands  are  of 
larger  diameter  and  closer  spacing  than  the  cross  strands,  the  latter  being 
chiefly  to  prevent  construction  cracks  in  the  concrete.  The  wires  are  elec- 
trically welded  at  every  intersection. 

183 


STYJUE"D 


£>OSS  \V/*JM 


0/V     -#. 

0"  & 


OA'    4- 
<XV  6"  CffA/TAk* 

Fig.  110. — Lock  Woven  Fabric  of  Standard  Gage.     (SV?  />. 


The  fabric  is  furnished  in  diameters  of  wire  ranging  from  i-io  inch  to 
3-10  inch,  and  with  spacing  between  the  strands  from  2  inches  up  to  20  inches. 

The  laying  of  the  fabric  in  the  Decauville  garage,  New  York,  is  illus- 
trated in  Fig.  109  (p.  183). 

LOCK  WOVEN  WIRE.— Lock  woven  wire  is  made  by  W.  N.  Wight 
&  Co.  It  is  similar  to  the  welded  wire  fabric,  except  that  instead  of  electric 
welding  the  intersections  are  bound  together  by  winding  them  with  soft  wire. 
The  various  gages  and  sizes  of  mesh  are  illustrated  full  size  in  Fig.  no. 

RIB  METAL. — Rib  metal,  illustrated  in  Fig.  noa,  and  made  by  the 
Trussed  Concrete  Steel  Co.,  consists  of  straight  bars  for  main  tension  members 
connected  by  light  metal  ties  which  serve  as  spacers,  and  also  are  useful  for 
cross  reinforcement. 

The  strength  of  the  metal  varies  with  the  spacing  of  the  ribs  so  as  to 
provide  various  areas  of  cross-section  of  steel  per  foot  of  width,  as  shown  in 
the  table. 

RIB    METAL    AREAS    AND    SECTIONS. 

Area  section  of  one  rib  =  0.9  square  inch. 


Size  No. 

Width  of 
Standard  Sheet 

Square  Feet  per  Lineal 
Foot  of 
Standard  Sheet 

Area  per  Foot 
of  Width 

2 

16  in. 

1-33 

.54sq.in. 

3 

24    " 

2.OO 

•36      " 

4 

32     " 

2.67 

.27      " 

5 

40    " 

3-33 

.216    " 

6 

48    " 

4.00 

.18      " 

7 

56    " 

4.67 

•154    " 

8 

64    " 

5  33 

•135    " 

Standard  Lengths — 8,  10,  12,  14  and  16  feet. 


FERROINCLAVE. — Ferroinclave,  invented  by  Mr.  Alexander  E.  Brown, 
of  the  Brown  Hoisting  Machinery  Company,  is  sheet  metal  bent  as  in  Fig. 
in,  and  spread  over  or  plastered  with  mortar  to  form  a  sheet  i^g  inches  thick. 
An  illustration  of  the  placing  of  ferroinclave  is  photographed  in  Fig.  112 


185 


TRUSS  METAL  LATH. — A  form  of  slit  metal  is  made  by  the  Truss 
Metal  Lath  Company,  with  the  strands  bent  to  receive  plaster,  as  shown  in 
Fig.  113. 

Truss  lath  comes  in  sheets  ranging  from  24  to  30  inches  wide  and  68 
to  112  inches  long,  and  in  three  gages. 


Fig.    llOa.— Rib   Metal.     (Sec  />.  185,) 

TRUSSIT. — Trussit  is  formed  by  expanded  metal  or  herringbone  lath 
bent  to  V-shape  section,  as  shown  in  Fig.  114.  It  is  manufactured  by  the 
General  Fireproofing  Company. 


/Waterproofing  felt 


Concrete}1  part  Portland  cement 
/  2  parts  sand 


|    n 

7      )- 

SSiHSSSpBlS 

7   .  t 

m 

SBmii^ttEB  Sff 

Ferroinclave 


'1  part  portland  cement 
'  Concrete]  2  parts  sand 

.Hair  as  required 


Fig.  111.— Section  of  Ferroinclave  Roof.     (See  p.  185.) 

HENNEBIQUE  SYSTEM.— One  of  the  pioneers  in  concrete  construc- 
tion in  Europe  is  Mr.  Hennebique,  in  France,  and  the  system  which  still  bears 
his  name  is  shown  in  Fig.  115. 

COLUMBIAN  SYSTEM.— The  special  forms  of  Columbian  bars  and 
methods  of  placing  them  are  illustrated  in  Fig.  116  (p.  190). 

186 


CUMMINGS  SYSTEM.— A  number  of  reinforcement  details  have  been 
invented  by  Mr.  Robert  A.  Cummings,  as  illustrated  in  Fig.  117  (p.  191). 

In  the  illustration  at  the  top  of  the  diagram  is  shown  the  Cummings 
method  of  forming  the  bent-up  bars  and  attaching  them  to  the  tension  bars. 
In  general  the  plan  is  to  provide  tension  bars  with  ends  specially  anchored, 


Fig.  112. — Placing  of  Ferroinclave  Roof.     (See  p.  185.} 

while  securely  attached  to  them  are  small  rods  horizontal  in  the  middle  of  the 
beam  or  girder,  but  bent  up,  as  indicated,  to  pass  across  the  top  of  the  beam 
and  form  inclined  inverted  U  bars  or  stirrups.  The  idea  is  more  clearly 


Fig.   113. — Truss  Lath. 

187 


(See  p.  186.} 


shown  in  the  sketches  below  of  "Arrangement  of  Steel."  The  "Supporting 
Chairs,"  placed  at  the  point  of  the  bending  up  of  the  rods,  are  also  drawn. 
For  the  slab  steel  another  type  of  supporting  chair  is  employed,  as  illustrated 
in  the  detail  sketch. 

The  Cummings  hooped  column  is  also  shown  in  the  upper  sketch,  and 
the  details  of  the  column  reinforcement  below.  Each  hoop  is  securely  at- 
tached to  the  upright  rods. 

UNIT  GIRDER  FRAME  SYSTEM.— A  type  of  reinforcement  for  beams 
and  girders,  which  is  built  in  the  shop  or  in  the  yard  where  the  building  is 
being  constructed,  is  shown  in  Fig.  118  (p.  192).  This  is  the  unit  girder 
frame,  manufactured  by  Tucker  &  Vinton. 

PIN-CONNECTED  SYSTEM.— A  modern  form  of  unit  reinforcement, 
made  by  the  General  Fireproofing  Company,  where  the  bars  are  made  into  a 
truss  before  placing  in  the  form,  is  shown  in  Fig.  119  (p.  193). 


Patented. 


Fig.  114.— Trussit.      (See  p.  186.) 

GABRIEL  SYSTEM.— Details  of  the  Gabriel  system,  as  laid  by  the  Ga- 
briel Reinforcement  Company,  are  shown  in  Fig.  120  (p.  193). 

ROEBLING  SYSTEM.— The  Roebling  system  is  employed  in  connec- 
tion with  a  structural  steel  frame  of  I-beam  or  girder  construction. 

For  all  flat  construction  of  floors,  the  reinforcing  system  used  consists 
of  flat  bars  placed  upon  edge,  secured  at  the  ends  to  the  steel  beams  and 
bridged  with  bar  separators.  The  object  of  the  edgewise  position  of  the  bars 

1 88 


is  the  increased  protection  thus  secured  to  the  reinforcing  steel.  With  this 
type  of  floor  the  structural  steel  frame  is  generally  completely  encased  with 
concrete. 

For  light  roof  construction  where  the  steel  work  need  not  be  protected, 
a  continuous  slab  is  built  over  the  beams,  reinforced  with  flat  steel  bars, 
3-16  by  i*4  inches,  placed  edgewise  and  held  in  position  by  spacers,  as  shown 
in  Fig  121  (p.  194). 

For  floor  construction  the  Roebling  Company  also  uses  segmental  arches 


Fig.   115. — Hennebique  System.     (See  p.  186.} 

of  cinder  concrete  laid  upon  permanent  stiffened  wire  lath  centering,  or  upon 
wood  centering  which  is  carried  on  steel  tees  and  supported  by  the  steel 
I-beams  of  the  floor  system,  which  are  generally  placed  about  7  feet  on  cen- 
ters. In  this  system  the  material  is  placed  upon  the  centering  without 
puddling  or  tamping,  in  order  to  obtain  a  light  porous  concrete  of  high  fire 
resisting  quality. 

MERRICK  SYSTEM.— To  lighten  the  weight  of  the  concrete  slab  Mr. 
Ernest  Merrick  has  designed  a  hollow  floor  construction,  as  illustrated  in 
Fig.  122  (p.  194).  Directly  upon  the  forms  a  2-inch  layer  of  concrete  is  placed, 

189 


and  before  this  has  set,  oblong  boxes  of  metal  fabric  of  small  mesh  are  laid 
horizontally,  with  the  reinforcing  rods  in  the  spaces  between  them,  and  the 
concrete  is  filled  in  between  the  boxes  and  around  the  reinforcing  rods  and 
covered  over  the  top  to  form  the  floor. 

MUSHROOM  SYSTEM.— The  mushroom  system  of  flat  slab  construc- 
tion is  the  invention  of  Mr.  C.  A.  P.  Turner.  The  rods  run  between  the 
columns  both  transversely  and  diagonally,  as  in  Fig.  123  (p.  195). 

The  interior  of  a  building  laid  by  this  system  and  showing  the  large 
column  capping  which  is  incident  to  it  is  illustrated  in  Fig.  124  (p.  196). 

FACTORY  MOLDED  CONCRETE. 

To  eliminate  the  cost  of  forms  and  at  the  same  time  to  utilize  to  best 
advantage  the  strength  of  the  concrete,  the  plan  has  been  adopted  of  molding 


Fig.  116.— Columbian  System.     (See  p.  186.) 

in  a  shop  the  various  members  for  a  concrete  house  or  factory,  and  transport- 
ing them  to  the  site  of  the  building  for  erection.  A  modification  of  this  plan 
is  followed  in  the  Textile  machine  shop,  described  in  Chapter  XI,  where  the 
columns  were  built  in  place,  but  the  girders  and  floor  beams  were  cast  sepa- 
rately by  the  Visintini  System  and  raised  to  place. 

Concrete  members  made  in  a  factory  are  subject  to  the  expense  of  trans- 

190 


portation  to  the  site  of  the  building  and  to  the  erection  cost,  but  over  against 
this  is  not  only  the  saving  in  form  construction,  but  also  the  economy  of 
manufacturing  the  concrete  in  a  stationary  plant  where  machinery  can  be 
utilized ;  the  use  of  light  sections  with  a  minimum  quantity  of  material ;  and 
the  advantage  of  an  initial  seasoning  of  the  concrete  which  eliminates  danger 
of  too  early  removal  of  forms  by  inexperienced  contractors. 

In  the  larger  cities  where  a  plant  can  supply  the  local  demand,  this  type 
of  construction  is  an  economical  form  of  fireproof  construction,  especially 
for  dwellings,  apartment  houses  and  small  factories. 

A  building  of  separately-molded  members  lacks  the  extreme  rigidity  of 


Co/v/7?/?  £e/>? force/ne/? f 
Fig.  117. — Details  of  Cummings  System.      (See  />.  187.) 


monolithic  reinforced  concrete  construction  unless  the  connections  can  be 
made  positively  unyielding,  but  even  with  ordinary  care  it  should  be  possible 
to  construct  at  least  as  stiff  a  building  as  ordinary  mill  construction  with  its 
brick  walls,  timber  columns  and  beams,  and  plank  floors. 

In  Europe  the  Siegwart  system  of  floor  construction  has  been  developed 
quite  extensively,  using  for  floor  slabs  a  series  of  adjacent  hollow  beams 
formed  by  the  use  of  collapsible  cores. 

The  Standard  system  has  been  devised  and  is  now  being  manufactured 
in  the  United  States  by  the  Standard  Building  Construction  Co.,  of  Pittsburgh, 

191 


s 

-*rf 

—•^ 

1 
I 
II 


J 
J 


(O^J 
lfc=l 


£= 


bJO 


IQ2 


(Patented; 

Fig.  119 — Pin-Connected  Girder  Frame.     (See  p.   188.) 

Penn.  The  general  scheme  is  to  build  floors  of  light  weight  I-shaped  or  T- 
shaped  joists  of  reinforced  concrete  to  replace  wood  joists  or  reinforced  con- 
crete slabs,  and  rest  the  ends  of  the  joists  upon  walls  made  of  vertical  inter- 
locking concrete  studding  or  concrete  blocks.  Columns  are  formed  in  the 
wall  in  light  construction  by  filling  the  hollows  between  the  vertical  studs, 
or  blocks,  with  concrete  reinforced  with  steel  rods.  For  heavy  buildings  the 
floor  joists  may  rest  upon  monolithic  reinforced  concrete  girders  and  columns, 
or  upon  structural  steel  girders  and  columns  fireproofed  in  the  factory  with 
concrete. 

Fig.  1243  (p.  197),  illustrates  a  floor  joist  resting  upon  2-piece  hollow 
block  walls.  The  standard  joist  section  shown  is  16  inches  wide  by  Sy2 
inches  deep,  with  horizontal  reinforcement  for  tension,  and  webbing  of  metal 
mesh  which  can  be  seen  in  the  photograph,  to  provide  for  shear  and  the 
stresses  which  are  liable  in  transportation.  Members  of  other  dimensions  are 
made  to  suit  the  span  and  loading  required. 


GABRIEL    SYSTEM 


REINFORCED  CONCRETE 


Fig.   120.— Gabriel  System.     (See  p.   i88.~) 
193 


A  nailing  piece  is  imbedded  in  the  top  of  the  joist,  as  shown  for  laying 
wooden  floors.  If  the  floor  is  to  have  concrete  finish,  the  joists  are  made 
I-shaped.  The  ceilings  are  plastered  upon  the  lower  flanges,  the  concrete 
being  left  rough  for  the  purpose. 

Three  styles  of  Standard  floor  construction  are  illustrated  in  Fig.  i2^b 
(p.  198).  The  top  floor  is  laid  with  joists  just  described,  the  two  middle 


Fig.  121.— Roebling  System.     (See  p.  188} 

floors  of  separately  molded  arches,  and  the  bottom  floor  of  cast  slabs  with 
reinforced  ribs  molded  on  the  bottom  surface.  The  thin  slabs  are  also  well 
adapted  for  roof  construction. 

An  important  feature  of  the  Standard  system  is  the  method  of  connect- 
ing the  individual  members.  The  reinforcement  is  allowed  to  project,  and  is 
mechanically  connected  after  placing.  The  connection  is  finally  imbedded  in 
fresh  concrete  so  as  to  give  strength  and  rigidity. 


Fig.  122. — Merrick  Floor  System.     (See  p.  189.) 

CONCRETE  BLOCK  WALLS. 

Frequently  concrete  blocks  are  cheaper  for  factory  walls  than  solid  con- 
crete, because  no  forms  are  required.  However,  if  used  in  combination  with 
reinforced  concrete  interior  construction  or  with  steel  beams,  they  must  be 
securely  connected  to  them  with  ties,  and  the  compressive  strength  of  the 

194 


blocks  carefully  figured  to  see  that  there  is  sufficient  area  of  concrete  to  carry 
the  weight. 

In  the  warehouse  at  Nashville,  Chapter  VIII,  concrete  blocks  are  utilized 
for  partitions. 

An  example  of  a  concrete  block  exterior  with  a  reinforced  concrete  interior 
construction  is  shown  in  Fig.  125  (p.  199).  This  illustrates  the  Salem  Laundry 
Building,  Salem,  Mass.,  of  which  Ballinger  and  Perrot  were  architects,  and 
Simpson  Brothers  Corporation,  builders.  This  has  a  reinforced  concrete  floor 
system  and  interior  columns  of  solid  concrete.  The  exterior  columns  are 
hollow  blocks  with  reinforcing  rods  running  through  the  openings  in  them 
and  surrounded  by  mortar  of  the  same  proportions  as  the  blocks  themselves 
so  as  to  form  solid  piers. 

CONCRETE  METAL  WALLS. 
A  type  of  wall  in  which  the  molds  also  form  the  permanent  reinforcement 


Fig.  123. — Mushroom  System.     (See  p.  190.) 

has  been  designed  and  patent  applied  for  by  Mr.  S.  H.  Lea.  Two  walls  of 
metal  lathing  are  erected  and  plastered  and  the  concrete  poured  between 
them,  as  shown  in  Fig.  126  (p.  200). 

SURFACE  FINISH. 

One  of  the  most  perplexing  features  of  reinforced  concrete  construction 

195 


is  to  obtain  a  pleasing  exterior  finish.  In  factory  construction  the  appearance 
of  the  building  is  usually  of  less  consequence  than  in  the  case  of  dwellings, 
and  yet  the  effect  must  not  be  distasteful  to  the  eye. 

Plastering  on  solid  concrete  or  on  concrete  blocks  is  unsatisfactory  in 
climates  where  the  temperature  in  the  winter  months  falls  below  freezing. 
A  very  thin  skin  of  cement  may  be  plastered  on  by  a  skilled  mechanic,  but 
this  is  apt  to  appear  streaked  and  prove  unsatisfactory  over  a  large  surface. 
If  the  surface  is  broken  by  moldings  or  joints  this  plan  can  be  used  with  fair 
results. 

An  excellent  finish,  although  a  somewhat  expensive  one,  is  obtained  by 
removing  the  surface  skin  of  cement  which  forms  against  the  molds  by  dress- 
ing it  with  a  pointed  hammer  of  a  pneumatic  tool.  This  method  is  illustrated 


Fig.  124.— Interior  of  Bovey  Building,  Built  by  the  Mushroom  System.     (See  p.  190.) 

in  Fig.  127  (p.  201),  and  a  photograph  of  the  same  wall,  taken  at  close  range, 
is  shown  in  Fig.  128  (p.  201). 

Another  style  of  finish  is  obtained  by  removing  the  wall  forms  within 
twenty-four  hours  and  immediately  washing  the  surface.  To  do  this  satis- 
factorily the  concrete  cannot  be  laid  very  wet,  or  the  water  will  run  down  over 
the  completed  surface.  A  similar  effect  is  obtained  with  acid  treatment. 

Another  type  of  finish,  which  tests  of  several  years  in  New  England  has 
shown  to  be  satisfactory  if  properly  applied,  is  the  slap-dash,  illustrated  in 
Fig.  129  (p.  202),  which  is  a  view  of  the  wall  of  the  Lynn  storage  warehouse, 

196 


built  by  the  Eastern  Expanded  Metal  Company,  and  described  in  Chapter  VI. 
The  wall  is  first  plastered  with  cement  mortar,  and  after  drying  the  slap-dash 
is  thrown  on. 

CONCRETE  PILE  FOUNDATIONS. 

In  certain  cases  concrete  piles  are  an  economical  substitute  for  wood  piles 
or  deep  pier  foundations.  Four  types  of  patented  reinforced  concrete  piles  are 
illustrated  in  the  following  figures: 

The  Simplex  pile,  manufactured  by  the  Simplex  Concrete  Piling  Co.,  is 
constructed  by  driving  a  hollow  shell  with  a  point  to  the  full  depth  and 
gradually  raising  the  shell  as  the  concrete  is  placed  in  the  hole  thus  made. 
The  process,  using  an  "alligator  point"  which  opens  when  the  shell  is  pulled, 
is  shown  in  Fig.  130  (p.  203).  Sometimes  a  solid  point  made  of  concrete  is 
used,  which  is  left  in  the  ground. 

The  Raymond  pile,  of  the  Raymond    Concrete    Pile    Co.,    is   formed   by 


Fig.  124a. — Standard  Floor  Joists  Resting  on  Concrete  Block  Walls.     (See  p.  193.} 

placing  concrete  in  a  thin  steel  tube.  The  tube  is  driven  with  a  collapsible 
core  within  it,  and  the  core  is  then  collapsed  and  withdrawn,  leaving  the  outer 
shell  to  be  filled  with  concrete.  The  driving  of  Raymond  piles  is  illustrated 
in  Fig.  131  (p.  204). 

The  corrugated  pile,  patented  by  Frank  B.  Gilbreth,  Fig.  132  (p.  205), 
is  cast  on  the  ground  and  driven  by  a  pile-driver  with  the  aid  of  a  water  jet. 
The  illustration  shows  a  corrugated  pile  in  process  of  driving  for  the  founda- 
tion of  the  warehouse  for  Mr.  John  Williams,  at  West  Twenty-seventh  street, 
New  York  city. 

197 


i98 


Fig.  125. — Concrete  Block  Walls,  Salem  Laundry.     (See  p.  /P5-) 

199 


EXPLANATION. 

A  =  Wire  Fabric. 

B  =  Spacing  Bar. 

C  =  Vertical  Member. 

D  =  Separator. 

O  =  Horizontal  Member. 

A  frame  of  the  desired  form 
is  erected  of  structural  steel  and 
covered  with  wire  fabric  as 
shown.  A  coating  of  cement  or 
mortar  is  then  applied  to  the 
outside  of  the  wire  fabric  which, 
upon  hardening,  forms  a  shell  of 
the  desired  outline,  which  may 
be  filled  in  with  concrete.  This 
method  of  construction  does  not 
require  the  us'e  of  forms  or 
molds,  thus  effecting  a  great 
saving  in  material  and  labor, 
besides  affording  a  strong,  well- 
finished  structure.  It  may  be 
employed  in  building  dams,  re- 
taining walls,  culverts  and  other 
structures. 


XI^, 


Fig.  126.—Lea's  Concrete  Metal  Wall  Construction.     (See  p. 

200 


Fig.  127. — Tooling  the  Surface  of  Friedenwald  Building  Walls.     (See  p.  196.} 


l?ig.  128. — Photograph  of  Tooled  Surface.     (See  p.  196.) 

201 


Fig.  129. — Photograph  of  Spatter  Dash  Finish  of  Lynn  Storage 
Warehouse.     (See  p.  196.) 

The  Gow  pile,  of  the  Chas.  R.  Gow  Co.,  Fig.  133  (p.  206),  has  an  en- 
larged footing  so  as  to  give  it  larger  bearing,  and  is  formed  by  washing  down 
a  tube  with  a  water  jet  to  a  firm  strata,  and  then  enlarging  the  bottom  of  the 
excavation  by  an  expanding  arrangement  to  form  the  base  of  the  pile.  The 
apparatus  is  withdrawn  and  the  space  filled  with  concrete. 

DRIVEN  PILES. — In  many  cases  where  too  many  boulders  are  not 
liable  to  be  encountered,  piles  of  rectangular  or  round  shape  are  built  hori- 
zontally upon  the  ground,  reinforced  with  steel  rods,  and,  after  setting  for  at 
least  a  month,  are  driven  with  a  pile  driver.  A  special  form  of  cap  is  re- 
quired to  break  the  force  of  the  ram  on  the  head  of  the  pile.  The  corrugated 
pile  (Fig.  132)  is  a  special  type  of  driven  pile. 

TANKS. 

Reinforced  concrete  is  being  used  to  a  large  extent  for  tanks  to  contain 
liquids.  They  require  careful  design  to  see  that  there  is  sufficient  steel  to 
resist  the  pressure,  and  also  very  careful  proportioning  and  placing  of  the 
concrete. 

A  system  of  square  tanks  or  vats  in  the  basement  of  the  American  Oak 
Leather  Company,  Cincinnati,  is  illustrated  in  Fig.  134.  These  are  6  feet  by 
8  feet  and  6  feet  deep,  with  reinforced  walls  4  inches  thick.  They  were  built 
in  groups  of  six  by  the  Ferro-Concrete  Construction  Company  with  specially 
prepared  aggregates.  These  vats,  after  over  a  year's  service,  have  given  entire 
satisfaction  and  show  no  signs  of  leakage. 

202 


1  !•:•' 


I>;   ^[j 


b 


fe 


2O4 


Fig.    132. — Gilbreth   Corrugated    Pile.    (See  p.  197.} 
205 


.0          O 


'X, 


,\ K'V    _,,_  ;;d       •    ,  .  V 


Fig.  133. — Gow  Pile.     (SV<?  />.  197.) 


206 


bfl 
SI 


2O7 


MISCELLANEOUS  BUILDINGS, 


209 


2IO 


o  o 

M  C 
O  .2 
ffi  3 


rtf  w 

rH  £ 

C1^ 

°  0> 

<C  c 


O  -o 

Si 


w 


w 


211 


< 

H 
O 
O 
O 
PQ 
r 

O 
O 

Q 
K 
< 

O  ^ 
«  c 

g* 

PL,  <j 
<•? 
*l 

*         *CL 

w  s 

P  Ls) 
<  ^ 

H 
fe 
O 

O 

00 


212 


2  » 

<l 
0| 

0.3 

«  a 

31 

at 
2" 


00 


213 


2I4 


r 

O 
o 


H   g 


" 


H   £3 
<   2 


bo 


215 


Q  8 

8'* 


O  £ 


fil 

w 


fa 

O  .2 


216 


O  - 


«  8, 

is 


«    g 
of]? 


g 


W  ^ 

§* 

tH        Ul 

§    u 

HH      bJD 


28  a 


o  § 

:* 

ffi  * 
H  o 


217 


218 


en 
W 
W 

M 
u 

a  ^ 

<u 

8! 


<   c 


<  S 
S'E 

!Z    6 

5  3 
o  o 


«•§ 

o« 

tH 
< 

H 

oT 
o 

CO 

M 

2 

I—  I 

ffi 


219 


S* 


W  5, 
^  t- 

ffi  ^ 

as 


220 


O  3 
o  « 


H  ' 
O 


O  ffi 

H  £ 
H  £ 

co  £ 

i:- 

H  £ 


221 


^ 
o  .-^ 

SI 


222 


223 


• 


C/D 


224 


MANUFACTURERS'  FURNITURE  EXCHANGE  BUILDING,  CHICAGO,  ILL. 

Dimensions  70  ft.  by  170  ft.    Wm.  Ernest  Walker,  Architect;  Mortimer  &  Tapper, 

Builders;  Condron  &  Sinks,  Consulting  Engineers. 

225 


SELBY  LEAD  SMELTING  PLANT,  SELBY,  CALIFORNIA. 
Lindgren-Hicks  Co.,  Builders;  John  B.  Leonard,  Consulting  Engineer. 


COLGATE  SOAP  FACTORY,  JERSEY  CITY,  N.  J. 

Dimensions  85  ft.  by  104  ft.    William  P.  Field,  Chief  Engineer; 

The  Concrete-Steel  Co.,  Builders. 

226 


SOAP  WAREHOUSE  OF  KIRKMAN  &  SON,  BROOKLYN,  N.  Y. 
Expanded   Metal  Engineering  Co.,  Engineers. 

227 


E    r 


S  if  I 


C  c  £ 

fl  1)     0> 

S  -  « 

^  OJ    g 

w  HO 


i 


228 


£ 

— -     1) 

<  2 


u 


H  fe 

03 

«  e 
o-g 


8- 


O  M 

2  .S 

Bl 
§« 


CO    DA 

B 

03    <l> 

H  -^ 

ffi 

O 


229 


O  g 

°J 
Q  "3 


"I 


r, 
O 


CO 


bfi 


«  S5 


w  8 

1-3      <U 

Hrl 


230 


231 


SZ    3 

8" 

u  - 


JO 


8 


< 

PH   '3) 


<->  6 


a  8 
s  s 


-a 


H  0 


PQ   .0 

^  I 

HH      W 

<  S 

s  e 

S 


232 


233 


234 


PRICES  SUBJECT  TO  CHAItOC 
WITHOUT  NOTICE: 


JOHNSON'S  SQUARE  AND  UNIVERSAL  FLAT  SECTIONS 
"°""«  FOR  REINFORCED  CONCRETE. 


MANUFACTURED    UNDER    UCENSEO    PATENTS 


.CCNTRAI.  *o*a 

MAIN    270» 
MAIN    i«3S 


EXPANDE  D  METAI,  &  CORRUGATE  D  BAR  Co. 


CABLE  ADDRESS:    COMRMM. 
Iddress  alt  Communications  to  Company. 


ST.  LOUIS, MO..USA,       August   28ft,    1907. 


Atlas  Portland  Cement  Ce.. 
New  York,  N.  T. 
Gentlemen :-- 

W«have  used  large  quantities  of  Atlas  Portland  cenent  aa 

purchased  -thrcu^i  your  several  agencies,   and  have  always  obtained  satisfactory/ 
and  unifera  results  from  its  us«  in  our  reinforced  concrete  work. 

Yours  very  truly, 
EXPANDED  METAL  AMD  CORRUGXTKD  BAR  COMPANY,, 


235 


.   M.  SMITH 


ill  010. 

Managing 


BOWLING    GREEN     BUILDING 
11     BROADWAY 


.-. ?«pt.  SA  1907.. 


The  Atlas  Portland  Cement  Co., 
30  Broad  St.. 

New  York  City. 
Sentleraen :- 

Answering  your  inquiry  of  Aug.  26th..  in  re- 
gard to  your  cement,  we  take  pleasure  in  advising  you 
that  we  have  used  a  considerable  quantity  with  satis- 
factory results. 

Your-^  truly. 

RAN  SOME  fc  SMITH..™* 
Par 


236 


UCOHPORAUD  SCFTIMM*  102  183(1 


Mart*    13.    1*07. 


»*   fl«i")*M    I    Sat*     :.> 

U  8^o*l»4/. 

*frt  Y-J-t  3Uf, 

GsntlsMn: 

Ar.ivsrlnj  /a*-  v-*-V  «•'  ts  *-e'.fler  the  factory  building  you  erected  for  u*  at 
Bayar.n*.   :.'.   :.,    ah:--.  11  791-1  141.  has  been  satisfactory;   and  also  *at  Iti  special  advant* 
ages  •  If   any  -   ar« :        I  bsj  '.a  say  the  building  ha§  been  •atlifaetory  in  aver/  wa;'. 

Aj  70<j  lr.o»,    j'.-.:s  /ou  »r»t'.*<l  «he  first  building  for  ui,  «•  hiT*  bad  you  erect 
addUtanat  *uildtr.;n  «i  t*.  t«  tn«  *^.J"-»g«t«  u-e  eoneiderably  larger  than  «ie  firet  »uildi*| 
you  coni*ruc"<J.       '*  »J'jll  not  for  a  moaent  ccntider  putting  up  any  building  other  than 
a  eoner«'.«  building   of  yur  c  "ftrjction. 

ABO.tj  etea   sf  *•   «p«ci«Jl  f«atjre>  that  occur  to  me,    are  - 

Firtt:        It*  b«ir,g  ab«ol-^telT  fire-proof.       This  »a»  fully  teeted  t«  ytv  «•!!  knov 
by  the   fire  •f.iar.   T>  'a  ad   in  our  Calcining  Department.       The  feed  pipe  conveying  the  fuel  oil 
to  the  burner,   bnse  ;•,»•*.  bacit  of  «h  e  burner  -  flooding  «ie  flocr  *V,h  b  irr.ing  ell  •  ukinc 
a  fir*  of  t*rrifi.;  :-.«v.  -  wittv   ill  expoied  setal  and  burning  all  eoabuetibl*  >»rtUle«i, 
etc.  that  tr. e  butU '..-.{  »t  that  tine  contained:     but  the  concrete  fcuildir.g  itaelf  etood  the 
te«t  aagr.lf ^er.tl/.   ami   ai  sur  property  ie  eurrdunded  by  itllli  of  Ihe  Standard  Oil  Co.. 
tfale  ii  a  parti:  ilarl/  •.  Va?ortar.t  feature  to  us,   and  ve  kno«  that  cur  >j»ldlng  ie  abeelut** 
If   flre-p.-ijC. 

3«c3.-4'.       -5>'.   Jf   '»?»'.-«,       Ho  expendUur*  under  thie  heading  ii  Bade  «  Ve  buildin| 
being  aonallti-  It  «M   ll'o   5 par.'.*.   *lne.   laprore*  with   age. 

>.'.rl;       S'.ii'ti-  .       A«  yoj  kno*  *•  oarry  terrifl*  loade  on  our  flttrt  •  en  our 
four*.    flo:r  f  irr/t -j   i  n'y*.  of  1430  l»i».  per  *q.  ft.      On  the  lorer  flcori  »•  hare  car- 
ried *•!•>•  :-.»»<!>-  *T.J  -.«  T'r  5.'.  e'.ratning  the  building  In  the  least. 


cry  u 


It  can  be  k»? 


•<  *  1*.  being  a  staple  aatte-  to  boie  and  varfi   it  rut. 
:  -•>>•.>  e:r.str.ntion  it  the  proper  conrtr-jctico  ar.d   tfcat  fee 
i'.»a.       Oa"  facto'y  buildings  am  certainly  a  fnvii-.cing 
u-e  «'*   ccr.crete  »19i  your  eyetea.   and  ttey  fcave  acre  fr.aa 


Vou-e  very  truly. 

Pacific  Coast  Bora*  Cc 


^   Manner. 


237 


WAITER.  T.  BALUNGER. 

ASSOC.AM  INST  OF  ARCHITECT* 
M.  AM.SOC.CE. 

CMUE    O.  PERROT. 

Assoc  AM. INST.  or  ARCHITECTS- 

ASSOC.  M.AM.SOC.C.  e. 


BALLINGER    &    PERROT 

ARCHITECTS  AND  ENGINEERS 

WOO  CHESTNUT  STREET 

PHILADELPHIA 


INDUSTRIAL    PLANTS 
INSTITUTIONAL     BUILDINGS 
RClNFORCED  CONCRETE  SPECIALISTS 


Auguet  27,    1907. 

Atlas  Portland  Cement  Company, 

30  Bread  St.,   Now  York,   N.   Y. 
Gentlemen:- 

In  reply  to  you*-    ,-d.vor  of  the  24th    inst.,    asking  UB  to  writs  you 
stating  what  success  -we  have  had  with    Atlas  Portland  Cenant,    would   say  that 
cement  has  been  used  in  considerable  of  our  work,    the  most  notable  instance  being 
that  of  •&!•  ei^it-story  Ketterliraus  Printing  House  at  Fourth   and  Arch    Btr*«t, 
Philadelphia,   erected  two  years  ago.       This  building  was  the  first  hi^i    reinforced 
concrete  building  e  -acted   In  Ph  iladeljhia.       There  were  all  sorts  of  prophecies 
of  disaster  made  to  -the  owners  and  ourselves  in  connection  with    it.       We.  are  glad 
to  say  that  -these  proved  to  be  false  prophecies,    and  that  the  building  is,   in 
every  way,   successful,    is  very  heavily  loaded  with  paper  and  heavy  printing  and 
lithographing  presses. 

Every  carload  of  cement  us«d  was  tested  according  to  eur  standard 
specifications,    and  met  the  tests  all  ri^it. 
Yours  truly, 


WB/K 


238 


L    KCTTtKUNUS.    »««»T 


a*  AN  CM  of  net  9 

MUTUAL^CSCRVC^BLDO. 


6,    1907. 


Th«  Atlas  Portland  Cement  Co., 

30  Broad  Street,  New  York,  N.  Y. 
Gentlemen: 

Answering  your  letter  of  February  28-th ,  aaklng  Aether  our  eigit  story 
reinforced  concrete  building,   in  which  your  cement  was  used,   is  satisfactory  or 
not,   I  am  pleased  to  state  that  it  is  all  that  I  could  expect  and  fully  up  to 
*at  Messrs.  Ballinger  A  Perrot,   Architects  and  Engineers,  predicted  that  it 
would  be. 

The  concrete  portion,  erected  la  1905,  is  in  every  way  superior  to  the 
portion  erected  in  1893,  which  was  of  steel  frame  fireprocfed  with  terra  cotta. 

The  reinforced  concrete  portion  of  the  same  size  cost  much   less  than 
the  other,  thou^i  the  cost  of  building  construction  was  ouch  greater  during  ihe 
latter  than  the  former  period. 

Our  opportunities  for  comparing  the  two  constructions  are  ideal,    and  we 
subject  both-  portions  to  equally  severe  usage,  having  large  printing  and  lithograph- 
ing presses,  weigiing  from  12  to  20  tons  on  the  third,    fourth  and  fifth   floors  of 
each  portion,   and  both   parts  being  about  equally  loaded  -jith  heavy  pape*  and  other 
material. 

We  believe  our  insurance  rates  are  lower  than  any  building  in  this 
section  of  the  city* 

Tour*  truly, 


239 


EASTERN  EXPANDED  METAL  CO.,   ""  '>•--• 

CHESTER  J.  HOQUE, 

MANUFACTURERS  OF  EXPANDED    METAL 

AND    CONTRACTORS    FOR 


.  .  REINFORCED   CONCRETE  .  . 

UILDING. 

STREET. 

BOSTON,     Sept.   3rd.   1907. 


PADDOCK   BUILDING. 

10t   TREMONT  STREET. 


Atlas  Portland  Cement  Co.. 

30  Broad  St..  New  York  City. 
Dear  Sirs:- 

In  reply  to  your  favor  of  the  3rd  inst.,  b»g  to  say  that  w«  h«r« 
used  and  ar»  using  Atlas  Portland  cement  on  some  of  our  most  important  vork  and 
hav*  found  it  uniformly  reliable  and  always  up  to  our  expectation.       IB  feel 
that  «htn  v«  u««  Atlas  in  eur  work  we  have  no  reason  to  fear  any  result?  but 
the  best. 

Tours  truly, 

KASTKRN  EXPANDED  METAL  CO. 


T/M  General  Manager, 


240 


LYNN  STORAGE 


Aug.   23.   1907. 


Atlas  Portland  Cement  Co., 
30  Bread   Str*«t, 

New  York,    N.    Yo 

Gentlsmen:- 

R^-lyi'i;  to  your  rsquest,   we  would    sav,    that  the  Easter^  Expanded  Metal 
Co.,    cf  Boston,    constructed   for  us   a  nix  stcr-/  building  for  general   storage 
purposes,   entirely  of   reinforced   cone  rote,'  us^ng   Atlas  Cenent   in  the  construct- 
ion.   and  we  are  ve>~y  nuch  pleased  with   tre  building. 

We  find  the  structure  to  b~e  ve1-/  fira  and   rigid  and  while  the  cost  aras 
sli^tly  gr«at«r  than  a  building  of  mill  construction  »ould  have  been,   thii.ia, 
amply  covered  by  the  fact  that  we  have  a  permanent  structure  absolutely  fire- 
proof,   and  a  lower  rate  of  insurance  for  ourselves  and  our  patrons;  besides  secur- 
ing a  large  amount  cf  business  irfiich   we  could  not  get  in  a  non-f ir*proof  building. 

Also,    we  note  -that    Jh  la  construction  gives  us  mud;    thinner  #alls  thar. 
w'uld  have  been  necessa*^  with   mill  construction,   ^.ich   increases  our  floor  area 
about  7  per  cent,    and  thus  adds  this  amount  te  «ur  earninp  capacity. 

The  construction  is  so  permanent  and    stable  that   the   "Depreciation   «r 
Plant"  account   is  practictilly  noticing. 

Yourc  ve»-/  truly. 

ouae   C>»,, 


Diet. 


24I 


•   »  «NBt"»OH    «l«T.  POST  AM»(K»QM  V  VttVI 

TVXOK  ritl.0   »«CV    T«»« 

THE  FERRO  CONCRETE  CONSTRUCTION  Co. 

RICHMOND  AND  HARRIET  STREETS 
CINCINNATI 


. 

August  26,    1907. 


Th«  iloorss-Coney   Supply  Co., 

Cincinnati,    Ihio. 
G«ntl«men:- 

W«  hav«  been  using  Atlas  Portland  Cement,   on  and  off,    for  the  last 
five  years.       During  this  time  we  have  tested  every  car  and  we  have  never  reject- 
ed a  car;    th«  cement  has  been  entirely  satisfactory   in  every  respect. 
Yours  very  truly, 

THE  FERRC  CCJlietfET?  CONSTRUCTION  CO. 


T7/CB  Secy.    A  Treas. 


Sec. 


242 


jtddresi  all  communication*  to  the  Company. 

THE  BULLOCK  ELECTRIC -MANUFACTURING  Co, 

OF  CINCINNATI.  U.  8.  A. 

DIRECT  AND  ALTERNATING  CURRENT  MACHINERY. 

CINCINNATI.  U.  «.  A.  May  I71h ,    1907. 


Ferro  Concrete  Construction  Co.. 

City. 
Gentlemen: 

Replying  to  your  latter  or  liay  llth.,   in  reference  to  the  extension 
to  our  9iop  No.  3  built  by  your  Company,  would  say  that  we  have  been  manufactur- 
ing in  this  building  for  the  past  year  and  one«half. 

Die  lower  floor  is  used  as  a  medium  machine  shop,   and  is  furnished 
with   two  10  ton  cranes  in  either  bay.       These  cranes  are  in  continual  operation 
and  so  far  the  concrete  column  and  brackets  carrying  the  crane  girders  have 
*cwed  no  signs  of  weakening,  having  st'~od  the.  continual  jar  of  the  crane  in 
a  roost  satisfactory  manner. 

Ihe  second  floor  of  this  diop  is  used  as  a  light  machine  shop,   and  our 
floor  loads  ars  excessive,   and  there  is-a  considerable  amount  of  high   speed 
machinery  in  operation  on  the  floor.       There  is  absolutely  no  vibration  and  the 
floor  has  *  own  no  signs  of  cracks.       In  some  portions  the  load  is  at  least 
50,4  greater  than  figured  on. 

One  of  our  principle   reasons  fcr  deciding  on  a  Ferro  Concrete  building 
was  that  at  the  time  cf  the  erection  of  this  building  ycu  wero  willing  to 
guarantee,   undor  bonus  and  penalty,   t<"  have  the  building  erected  in  90  days  less 
line  than  we  could  get  deliveries  started  on  the  necessary  steel  for  girders, 
columns,    etc.   in  a  brick  steel  construction. 

You  re  v«ry  truly, 

Ihe  Bullock  Electric  Mfg.  Co. 


Supe  rintendenf; 
243 


i$feM&mK 


CONCRETE 

RANSOME    SYSTEM, 

H.c.TORMER.ae.  P......NT.  H  BROADWAY, 

0  H.DIXON.  C  E.  «~f«.usuP«.>,-.Tt*0eNT 


Mia*  Portland  Ctm«nt  Co., 
#30  Broad  St.* 

K»»  Y»rk  City. 


W«hav«  ua*d  I*TTB»  quantities  of  Atlas  Portland  Ctmtnt  in  such    reinforc- 
ed eoncr*t«  buildings  as  the  J.  B.  King  ft  Company  Buildings,   Staien  Island;  1h* 
Keuffel  *  Baser  Buildings,  Hebo:<en.   N.  J.,   and  the  Buih  Terminal  Company  Buildings, 
BrcoVlyn.   and  the  excellent  ecndition  of  this  work  to-day  is  ample  deeonatrvtitft 
of  the  me^Ue  of  you'  ceaent  f  or  bi£»-gra<i»  worl. 

Very  Wuly 


H.C.T. 


244 


BUSH  TERMINAL  COMPANY. 

QFFICEOFTHE  PRESIDENT 

IOO    BROAD    STREET. 


PRESIDENT. 


NEW  YORK. Hay  29,  1907. 

Atlas  Portland  Cement  Co., 

30  Broad  S  t..  H.Y.Clty. 
Gentlemen:- 

Your  letter  of  April  24th,  asking  for  an  expression  from  us  as 
to  our  views  on  concrete  construction  for  factory  buildings,  was  duly 
referred  to  me,  "but  in  some  way  mislaid,  and  has  juat  come  to  hand* 

We  were  chiefly  influenced  to  adopt  reinforced  concrete  conatruo- 
tion  for  our  Uodel  Loft  and  Factory  Buildings,  because  of  our  opinion  that, 
at  the  present  relative  prices  of  cement  and  steel,   concrete  buildings 
represented  the  most  economical  form  of  fire-proof  construction,   and  of  the 
additional  advantage  for  touildings,where  the   operation  of  machines  of  var- 
ious types    was    employed  upon  different  floors,   the  concrete  buildings, 
being  practically  of  monolithic  construction,  were  free  from  vibration 
which  is  an  objectiobale  feature  in  the  ordinary  stefcl  fire-proof  building, 
used  for  similar  purposes.     The  effect  upon  our  insurance  has  been  impor- 
tant, but  this  has  been  due  to  the  fire-proof  character  of  the  buildings, rath- 
er than  to  any  particular  method  of   construction. 

Yours  very  truly, 


President- 
1TB 


245 


oerooiT.  MICH. 
•  ITTS8URG.PA 
HKtRVILCI.ON* 
CABLE  AOOHCM 

iNCRETE.OErPOiT 


Detroit,Micli,  S:*  27,  1907. 


Atlas  Portlcwd  Cement  Co., 
30  Broad  Street, 

Ne«  York  City. 
Gentlemen :- 

It  gives  us  pleasure  to  be  able  te  endorse  Atlas  Portland  Cement  without 
aental  reservation  or  evasion. 

Every  bit, of  cement  used  under  the  Kshn  System  ia  subjected  to  rigid 
scientific  tests,   and  that  Atlas  Portland  Cement  has  been  used  in  several  hundred 
Kshn  System  structures  is  p  roof  positive  of  its  excellent  qualities. 

Our  laboratory  records  are  as  gcod  an  endorsement  as  any  customer  could 
desire. 

Yours  very  truly, 

TRUSSED  CONCRETE  STEEL  COMPANY 


J 


President. 


246 


16, 


Atlas  Portland  Cement  Company, 
30  Broad  Street, 

New  York  City. 
Gentlemen:- 

In  answer  to  your  Inquiry  as  to  advantages  of  concrete 

construction,   em  pleased  to  state  -that  our  original  factory  was  about  150,000  sq. 
ft.  of  brick  buildings  and  mill  construction  floor  space. 

lien  we  came  to  enlargements,  we  were  impressed  by  the 

advantages  of  concrete  construction,   and  in  the  past  two  years  have  added  to  our 
factory  upwards  of  250,000  sq.  ft.   of  floor  space  of  the  Trussed  Concrete  Steel 
Company's  construction  and  have  now  improcess  upwards  of  100,000  sq.  ft.  more, 
to  you  will  see  our  belief  in  the  concrete  construction  is  very  deeply  rooted. 
First,  in  my  judgment,  you  get  the  best  fire-proof,  conditions.       Second,  you  avoid 
the  delay  of  waiting  for  steel  and  work  proceeds  immediately  and  expeditiously  and 
without  the  disturbance  of  riveting.      Third,  the  ft  op  light  conditions  are  much 
better  with  the  Kahn- system' of  concrete  construction  "than  with  brick  work,  because 
the  piers  are  smaller.       Ihe  conditions  in  this  respect  are  fully  as  good  as  steel 
const ruction. 

In  addition  to  our  upwards  of  ten  acres  of  factory  floor 

space  in  Detroit,  there  is  now  nearing  completion  our  new  retail  store  in  New 
York  City,  Corner  Broadway  and  61st  Street,  also  of  the  Kahn  reinforced  concrete 
construction,  the  same  as  we  use  here  and  also  built  by  the  Trussed  Concrete  Steel 
Company.      We  have  other  work  in  contemplation  in  ^ich  we  shall,  of  course,  continue 
to  use  the  Kahn  system  of  reinforced  concrete  construction. 
Very  truly  yours, 

MOTOR  CAR  COMPANY. 


HBJ-.SU 
642. 


247 


A.ODRKS9    AJLt-  COMMUNICATIONS  TO  THE  COMr 


VILLIAM    MUKSER, 


BDWIN    TMACRKR. 


CONCRETE-STEEL  ENGINEERING  COMPANY, 


CONCRETE-STEKI. 
BRIDGES 

VIADUCTS, 

SUBWAYS, 
GIRDERS,   SEWERS?, 
KTX>ORS,    ROOKS, 

DOCIvS, 
AND 
ALL  KINDS  Of 

CONCRETK-STEKL 

CONSTR  UCT  ION. 


TH ACKER  AND 

DIAMOND     BARS 

FOR 

RE-KNEORCINO 
CONCRETE. 


FOUNDATIONS. 


N   ARCH   CONSTRUCTION    COMPANY 

CONSULTING    ENGINEERS. 


OWNERS    OK 

MELAN,   THACHKR. 

VON    EMPEROER. 

MUESKR 

AND 
OTHER    PATENTS. 


PLANS,  SPECIFICATIONS 
ESTIMATKS  FURNISHED 


AL  OFFICKSJ- 

ROW 

BUILDING, 
YORK. 

E,    3303    COKTLAMDT. 


NEW    YORK 


Aug.   28th 


Tht  Atlas  Portland  Caaent  Company, 
D«partn«nt  of  Publicity. 

30  3r&ad   Str««t, 

\'«w  York  City. 
Gentl«m«n:- 

Y*ur  a«n«rtth&«  b««n  uaod  in  large  qtiantitle.  in  our  ccncr«t« -steel 
arch  brtdgaa,  built  In  different  aectione  of  1he  country  and  has  alwaye  given 
eomplau  »*ti«f «*.ifl«.  V«  consider  it  a  firet  class  cement  in  every  way. 

Very  truly  yours, 
CONCRBTR-STESL  INOINKERTNG  COMPLY 


248 


SINGEING   MACHIKCS. 

FULL  FASHIONED    KNITTING   MACHINES  (COTTON  SYSTEM) 


ifor.   6.  1907 


Ihe  Atlas  Portland  Cement  Company, 

No.  30  Bread  Street, 

N»w  Tork  City,  N.  Y. 
Gentlemen;* 

We  are  pleased  to  advise  you  that  the  eonerete-ateel  factory  buiUiog* 
which  we  erected  about  two  years  ago,  of  the   'Vieintioi    oonatruction, .in  accordance) 
with  plans  prepared  by  the  Cone  rate-Steel  Engineering  Company  of  New  Tork  City, 
has  given  us  very  good  satisfaction. 

Ihe  writer  saw  an  ejfcibition  in  St.  Louis  in  1903,  *ich  had  been  arranged 
by  the  Concreta-Steel  Engineering  Company,   and  waich   exhibited  the  principles  of 
the   'Visintini*  aystea.      We  were  then  contemplating  the  erection  of  a  factory 
building  for  li^it  manufacturing  purposes,  and  one  of  our  main  objects  was  to  put 
up  a  building  which  would  be  aa  nearly  fire  proof  as  possible,  at  moderat«  coat,  and 
vhich  would  carry  a  low  insurance  rate  without  the  installation  of  a  sprinkling 
syst«o.      This  object  has  been  accomplished  by  the  building  which  we  erected,      to 
have  a  rate  of  twenty  cents  for  <h«  building  and  .forty  cents  for  the  contents,  fro*  tb« 
atoek  companies,  «hi<*i  rat*  ia  considerably  leas  than  half  of  what  we  paid  heretofore 
on  our  other  buildings. 

Ihe  building  was  put  up  during  the  winter  of  1904,  and.  except  a  few 
days  of  extremely  bad  weather,   the  operations  were  continued  uninterrupted  evea 
when  the  thermometer  was  down  to  almost  zero.      we  had  all  the  work  done  by  day  work 
or  sub-contract,  and  we  are  satisfied  that  we  hare  a  first  class  job  and  a  good 
investment.       Ihe  building  presents  a  nice  appearance,   and  the  contrast  between  the 
red  brick  curtain  walls  of  the  panels  and  the  cement  columns  and  wall  beams  ia 
particularly  pleasing. 

Very  truly  yours, 
NEP..:;s  Textile  Machine  Work*. 


249 


THE  GENERAL  FII^EPI^OOFING  Go. 


tHE  GtN  tftAL  rift  CPROOflNO  CO.  SY3T£M  OF  R£IH  FORCED  CONC«tT«. 


ST.  LOUIS  .WASHINGTON  HtW  ORLEANS  CHICAGO 

YOUNGSTOWN.  OHIO,      Aug.  27,  07. 


Mian  Portland  Cement  Co.. 
30  Broad  St., 

New  York  City. 
Gentlemen : - 

As  Atlas  Portland  Cement  was  used  in  the  construction  of  -the  Orunewald 
Hotel,   New  Orleans,   La.,   and  the  Carpenter  Siop  building  for  the  National  Cash 
Register  Co.,  Dayton,   0.,   in  connection  wilh   reinforcing  steel  furnished  by  this 
company,  we  believe  the  accompanying  jhrtegraphs  may  be  of  interest  to  you.       The 
two  buildings  are  respectively  excellent  illustrations  of  leng  span  fireproof ing 
and  entire,  reinforced  concrete  construction. 

Our  observation  of  the  concrete  work  en  these  buildings  is  in  harmony 
with   ourhigi   opinion  of  Atlas  Cement  and  you  are  a^  1  ibe-ty  to  use  these  photo- 
graphs ae  you  may  desire. 

Yeurs  truly, 

The  General  Fireproo^Jmg  Company. 
f)/ 


250 


d/2/1907, 


The  Atlas  Portland  Cement  Co., 

New  York. 
Dear  Sirs:- 

Replying  tc  your  valued  favor  cf  recent  date,  we  beg  to  advise  -that  we 
are  constructing  a  five  story  concrete  building.       We  thou^it  over  the  matter  very 
seriously,   and  after  due  consideration,  decided  tc  build  concrete  on  account  of  its 
stability,   durability  and  its  sanitary  characteristics,   and  last,  but  not  least, 
we  believe  it  is  more  economical  in  the  end  on  account  of  reduction  in  insurance  rates. 
We  are  seriously  considering  carrying  no  insurance  whatever,   for  the  building,   as  far 
as  we  can  see,    is  fireproof  to  the  extent  that  we  believe  it  would  be  impossible  to  set 
it  afire,     and  we  dc  not  think  the  cost  ever  ten  tc  fifteen  percent  above  the  coet  cf 
rail!  constructi;.n,   ard  we  go  fu»~ther  in  saying  that  v/e   recommend  everyone  Mho  contem- 
plates the  erection  of  a  building  for  warehouse  purposes  tc  build  of  concrete. 

Yours  truly, 


251 


Announcement 

For  the  benefit  of  those  who 
desire  to  make  lasting  im- 
provements about  the 

FARM, 
FACTORY   or 
HOME, 

and  as  a  guide  to  those  who 
contemplate  new  construc- 
tions, we  have  published  the 
following  books: 


252 


For  the   Suburbanite  and  Farmer 

"CONCRETE.  CONSTRUCTION  ABOUT  THE 
HOME,  AND  ON  THE  FARM," 

a  book  containing  directions  for  making  and  handling  concrete, 
also  many  specifications,  sectional  drawings  and  photographs  of 
the  smaller  constructions  that  can  be  built  by  the  layman  with- 
out skilled  labor. 

Paper-bound  copies,  free  upon  request. 
Cloth-bound  copies,  2$c.  each. 


For  the   Mechanic  and  Artisan 

"CONCRETE  COTTAGES," 

a  sixteen-page  pamphlet  showing  photographs,  floor  plans  and 
specifications  for  small  concrete  houses  ranging  in   price  from 

$1,500.00  to  $4,000.00. 

Copies  sent  free  upon  request. 


For   the   Homebuilder   and  Investor 

"CONCRETE  COUNTRY  RESIDENCES," 

a  book  containing  photographs  and  floor  plans  of  over  150 
Concrete  Houses,  ranging  in  price  from  $2,000.00  to 
$200,000.00.  These  houses  not  only  show  a  large  variety  of 
design,  but  are  of  several  different  systems  of  concrete  con- 
struction. They  are  not  imaginary  sketches,  but  houses  already 
built  and  designed  by  the  best  architects  in  the  country. 

Copies  (168 pages,  size  io.ri2)  will  be  sent  by  express 
prepaid  upon  receipt  of  $1.00. 


THE   ATLAS   PORTLAND   CEMENT   CO. 

30  Broad  Street,  New  York 

253 


THE  STANDARD  AMERICAN  BRAND 


,* PORTLAND". 

ATLAS 

CEMENT 


ALWAYS  UNIFORM 


UNIVERSITY  OF  CALIFORNIA  LIBRARY 
BERKELEY 

Return  to  desk  from  which  borrowed. 
This  book  is  DUE  on  the  last  date  stamped  below. 

— ENGINEERING  LIBRARY 


JUN  1     1948 

OCT  1*  1948 
OCT  8    19S2 


LD  21-100m-9,'47(A5702sl6)476 


YD  07423 


789451 


JBnglneering 
Library 


UNIVERSITY  OF  CALIFORNIA  LIBRARY 


